# History of Ghostscript versions 4.n

## Table of contents

> - Version 4.81 (6/1/97)
>   - Documentation, Procedures, Utilities, Drivers, Platforms, Interpreter, Library
> - Version 4.80 (limited) (5/28/97)
>   - Documentation, Procedures, Utilities, Drivers, Platforms, Fonts, Interpreter, Streams, Library
> - Version 4.74 (limited) (5/5/97)
>   - Documentation, Utilities, Drivers, Interpreter, Streams, Library
> - Version 4.73 (limited) (4/19/97)
>   - Documentation, Procedures, Utilities, Drivers, Platforms, Interpreter, Interpreter (PDF), Streams, Library
> - Version 4.72 (limited) (4/14/97)
>   - Documentation, Procedures, Drivers, Platforms, Interpreter, Interpreter (PDF), Streams, Library
> - Version 4.71 (limited) (3/31/97)
>   - Documentation, Procedures, Drivers, Interpreter, Streams, Library
> - Version 4.70 (limited) (3/26/97)
>   - Documentation, Procedures, Drivers, Platforms, Interpreter, Interpreter (PDF), Streams, Library
> - Version 4.61 (limited) (3/13/97)
>   - Documentation, Procedures, Drivers, Platforms, Interpreter, Interpreter (PDF), Streams, Library
> - Version 4.60 (limited) (3/2/97)
>   - Documentation, Procedures, Drivers, Platforms, Fonts, Interpreter, Interpreter (PDF), Streams, Library
> - Version 4.51 (limited) (2/9/97)
>   - Procedures, Drivers, Platforms, Interpreter, Streams, Library
> - Version 4.50 (limited) (1/31/97)
>   - Documentation, Procedures, Drivers, Platforms, Interpreter, Streams, Library
> - Version 4.41 (private) (1/21/97)
>   - Procedures, Drivers, Fonts, Interpreter, Streams, Library
> - Version 4.40 (private) (1/13/97)
>   - Documentation, Utilities, Drivers, Interpreter, Interpreter (PDF), Library
> - Version 4.39 (limited) (1/1/97)
>   - Documentation, Procedures, Utilities, Drivers, Interpreter, Streams, Library
> - Version 4.38 (limited) (12/20/96)
>   - Interpreter, Streams, Library
> - Version 4.37 (limited) (12/10/96)
>   - Fonts, Interpreter, Interpreter (PDF), Library
> - Version 4.36 (limited) (12/3/96)
>   - Documentation, Drivers, Interpreter, Library
> - Version 4.35 (limited) (11/24/96)
>   - Documentation, Procedures, Interpreter, Streams, Library
> - Version 4.34 (limited) (11/18/96)
>   - Documentation, Procedures, Drivers, Interpreter, Streams, Library
> - Version 4.33 (limited) (11/6/96)
>   - Documentation, Procedures, Interpreter, Library
> - Version 4.32 (limited) (11/1/96)
>   - Documentation, Drivers, Platforms, Fonts, Interpreter, Library
> - Version 4.31 (limited) (10/27/96)
>   - Documentation, Procedures, Platforms, Interpreter, Interpreter (PDF), Streams, Library
> - Version 4.30 (limited) (10/23/96)
>   - Documentation, Drivers, Platforms, Fonts, Interpreter, Library
> - Version 4.21 (limited) (10/17/96)
>   - Documentation, Procedures, Drivers, Platforms, Fonts, Interpreter, Library
> - Version 4.20 (limited) (10/13/96)
>   - Documentation, Procedures, Utilities, Drivers, Interpreter, Library
> - Version 4.10 (limited) (9/25/96)
>   - Documentation, Utilities, Drivers, Interpreter, Interpreter (PDF), Library
> - Version 4.03 (9/23/96)
>   - Documentation, Procedures, Drivers, Fonts, Streams
> - Version 4.02 (9/19/96)
>   - Documentation, Procedures, Utilities, Drivers, Platforms, Interpreter, Interpreter (PDF), Streams, Library
> - Version 4.01 (7/10/96)
>   - Documentation, Procedures, Utilities, Platforms, Platforms, Interpreter, Library
> - Version 4.0 (6/28/96)
>   - Documentation, Procedures, Utilities, Drivers, Platforms, Interpreter, Streams, Library

This document is a history of Ghostscript releases numbered 4.n. For more recent changes, see the the other history documents and, for the latest versions, the news:

> News
> History of Ghostscript versions 4.n (this document)
> History of Ghostscript versions 3.n
> History of Ghostscript versions 2.n
> History of Ghostscript versions 1.n

For other information, see the Ghostscript overview.

## Version 4.81 (6/1/97)

This is a last-minute set of bug fixes before the 5.0 release.

### Documentation

    Adds some overlooked helpers to the list.  (helpers.txt)

### Procedures

    Makes a distinction between 2-part and 3-digit version numbers.
    (version.mak, vms.mak)

### Utilities

    Develops the Type 1 to CFF converter a little further; it is still NOT
    USABLE.  (t1tot2.ps)

    Removes the pstoppm.ps script, since the p*m drivers supersede it.
    (pstoppm.ps, unix-end.mak)

### Drivers

    Fixes bugs:
    	- The PDF writer sometimes omitted an ET command before setting the
    clip path.  (gdevpdf.c)
    	- The PDF writer didn't initialize the "vector" state, leading to
    some redundant output (performance bug only).  (gdevpdf.c)
    	- The PDF writer wrote clip paths even when they included the entire
    page (performance bug only).  (gdevpdf.c)

    Changes the PDF writer so that it recognizes not only the 14 built-in fonts
    but any font with the same UniqueID and metrics.  This covers some common
    cases of re-registering a font with a variant Encoding.  (gs_pdfwr.ps)

### Platforms

    Fixes bugs:
    	- SEARCH_HERE_FIRST was accidentally set to 0 on MS Windows
    platforms.  (bcwin32.mak, msvc4.mak, msvc5.mak, watcw32.mak)

    Adds code to remove "" around arguments in the command line passed to
    WinMain (MS Windows platforms).  (dwmain.cpp, dwmainc.cpp)

### Interpreter

    Fixes bugs:
    	- setsystemparams was broken.  (gs_lev2.ps)
    	- restore was broken if -dNOBIND was invoked.  (gs_dps1.ps)
    	- deviceinfo returned much more information than it should.
    (gs_dps.ps)
    	- The fix for the default EndPage procedures not popping their page
    count operand from the stack was wrong.  (gs_init.ps, gs_setpd.ps)

### Library

    Fixes bugs:
    	- The saved character origin took the translation component of the
    FontMatrix into account, which caused charpath on fonts with non-zero
    translation in the FontMatrix to produce incorrect results.  (gschar.c)

    Removes incorrect access attributes on a couple of files.  (gdevpdfm.c,
    gxclist.h)

## Version 4.80 (limited) (5/28/97)

This is the candidate fileset for the 5.0 release.

### Documentation

    Fixes bugs:
    	- The one-line description of the color image rendering module was
    incorrect.  (gximage3.c)
    	- Some of the VMS documentation was out of date.  (make.txt,
    use.txt)
    	- The description of the file name separator for -sFONTMAP= was
    wrong.  (use.txt)
    	- PSFile was misspelled PSfile.  (use.txt)
    	- There were some minor typos.  (gstype1.h)
    	- The build instructions had a lot of obsolete information for PC
    environments, and didn't cover Microsoft Visual C++.  (make.txt)

    Explains that -sPAPERSIZE= only specifies the default papersize, and that
    forcing a particular paper size also requires -dFIXEDMEDIA.  (use.txt)

    Adds information about building with GNU make on OpenVMS.  (make.txt)

    Clarifies the meaning of EOFC for streams.  (strimpl.h)

    Documents the new dictionary argument for the eexecDecode filter.
    (language.doc)

### Procedures

    Fixes bugs:
    	- gs_epsf.ps didn't get installed on Unix systems.  (unix-end.mak)
    	- The code wouldn't build with libpng 0.95b.  (libpng.mak)
    	- One of the VMS scripts used CC_QUAL instead of CC_DEF.
    (vms-cc.mak)
    	- version.mak wasn't included in a dependency list.  (unix-end.mak)

    Brings the VMS DCL script up to date again (for the last time, we hope).
    (vms.mak)

    Modifies all platform-independent uses of upper-case command line arguments
    to deal properly with VMS, where the shell converts all command line
    arguments to lower case, without requiring quotation.  (devs.mak, gs.mak,
    int.mak, lib.mak, zlib.mak)

    Moves the compilation rules for the third-party libraries into gs.mak, so
    they can be used to compile the callers as well.  (gs.mak, jpeg.mak,
    libpng.mak, zlib.mak)

    Adds a set of files that allow building on OpenVMS using GNU make (slightly
    patched).  The timing on this is unfortunate, but we've wanted this for a
    very long time.  NOTE: be sure to look in the OpenVMS section of make.txt
    for information on patching GNU make.  (openvms.mak, append_l.com,
    rm_all.com, rm_one.com, copy_one.com)

    Adds new makefiles for building on 32-bit Windows with Borland, Watcom, and
    Microsoft Visual C++ (versions 4.x and 5.0).  The timing on this is
    unfortunate too, but having this capability is so important that we couldn't
    pass it up.  (bcwin32.mak, msvc4.mak, msvc5.mak, msvccom.mak, watcw32.mak,
    wincom.mak)

    Removes now-obsolete makefiles.  (dwcommon.mak, msc.mak, msvcwint.mak,
    mscbegin.bat, watcwin.mak)

### Utilities

    Extends echogs to work in VMS environments, where the shell converts all
    command line arguments to lower case, without requiring quotation.
    (echogs.c)

    Adds a sketch of a utility for converting Type 1 fonts to CFF.  DOESN'T WORK
    YET: DON'T TRY TO USE IT.  (t1tot2.ps, type1ops.ps, writecff.ps)

### Drivers

    Fixes bugs:
    	- A type declaration wasn't compatible with libpng 0.95.
    (gdevpng.c)
    	- kshow wasn't handled properly when producing PDF output.
    (gs_pdfwr.ps)
    	- The PDF writer put out unnecessary ET/BT commands.  (gdevpdfx.h,
    gdevpdf.c, gdevpdfi.c, gdevpdfm.c, gdevpdft.c)
    	- The PCL XL writer put out real numbers for the miter limit, which
    are not allowed (!).  (gdevpx.c)
    	- The PCL XL writer didn't combine successive curves into a single
    curve command (performance bug only).  (gdevpx.c)
    	- The PCL XL writer could write uncompressed images with a tag
    saying they were compressed.  (gdevpx.c)
    	- The PCL XL writer always selected U.S. letter paper, rather than
    the requested size.  (gdevpxen.h, gdevpx.c)
    	- The PCL XL writer reselected the paper size on every page, even if
    it hadn't changed.  (gdevpx.c)
    	- The PCL XL writer always used shorts for line and curve
    coordinates, rather than using bytes when possible (performance bug only).
    (gdevpx.c)
    	- Because of a compiler bug, a macro with argument conflicted with a
    variable name.  (gdevpdfx.h, gdevpdf.c)
    	- A picky compiler objected to an extern for an undefined structure.
    (gdevpsdf.h)
    	- The PDF writer sometimes didn't reset the clipping path, causing
    bitmaps or rectangle to disappear.  (gdevpdf.c, gdevpdfi.c)
    	- The PDF writer produced invalid output if the first page was
    blank.  (gdevpdf.c)
    	- The AutoRotatePages parameter for PostScript and PDF output (which
    doesn't actually do anything yet) incorrectly expected a Boolean value
    rather than an enumeration.  (gdevpsdf.h, gdevpsdf.c)
    	- Some places returned -1 for an error without calling gs_note_error
    or gs_return_error.  (gdevm1.c, gdevmpla.c, gdevrun.c, gxclpath.c)
    	- The PCL XL writer produced extremely large files because it didn't
    download character bitmaps.  (OK, this isn't really a bug fix.)  (gdevpx.c)
    	- The forwarding implementation of get_page_device didn't do the
    right thing.  (gdevnfwd.c)
    	- The x11alpha device didn't implement get_params properly, leading
    to anomalous behavior.  (gdevxalt.c)
    	- The PDF writer produced incorrect Count values for outlines: the
    count only counted descendant leaves, omitting intermediate nodes.
    (gdevpdfm.c)

    Removes an assumption that images have at most 4 components.  (gdevpdfi.c)

    Adds an x11gray2 device, primarily for debugging.  (devs.mak, gdevxalt.c)

    Updates the unified printer driver with a newer version.  (uninfo.ps,
    gdevupd.c, *.upp)

### Platforms

    Adds the P*M devices and the X11 devices (commented out) to the OS/2
    makefile.  (os2.mak)

    Updates the MS Windows platform to be compatible with Microsoft Visual C++
    (as well as Watcom and Borland compilers).  (gsdll32.def, gdevmswn.h,
    gp_mswin.h, gsdll.h, dwimg.cpp, dwmain.cpp, dwmainc.cpp, dwtext.cpp,
    gdevwdib.c, gdevwprn.c, gdevwpr2.c, gp_mswin.c, gsdll.c)

### Fonts

    Fixes bugs:
    	- Certain synthetic fonts incorrectly were loaded into local rather
    than global VM.  (These fonts are not part of the standard distribution.)
    (gs_fonts.ps, gs_pfile.ps, *ss*.ps)

### Interpreter

    Fixes bugs:
    	- The FAKEFONTS scan could leave junk on the stack.  (gs_fonts.ps)
    	- Dynamically loading known encodings on demand left junk on the
    stack, causing a typecheck error.  (gs_res.ps)
    	- Some 'static' declarations were missing (gcc lossage).  (iname.c)
    	- Some internal operators didn't have names, leading to unhelpful
    error printout.  (zfileio.c)
    	- The resource "operators" didn't always restore the stacks properly
    on an error.  (gs_res.ps)
    	- The CID font code left a garbage value on the stack during
    loading.  (gs_cidfn.ps)
    	- The defineresource implementation for built-in resources like
    FMapType didn't leave the resource "value" on the stack.  (gs_res.ps)
    	- If an operator defined by a procedure was bound into a packed
    procedure, the stack-protection feature wasn't effective.  (interp.c)
    	- findfont didn't restore the stack if it failed.  (gs_res.ps)
    	- The showpage count passed to the BeginPage and EndPage procedures
    was incremented only if a page was printed, rather than for every invocation
    of showpage.  (gs_init.ps, zdevice2.c)
    	- The default EndPage procedures didn't pop their page count operand
    from the stack.  (gs_init.ps, gs_setpd.ps)
    	- If the argument of findfont wasn't a name or a string, and no font
    with that key had been registered, an error occurred.  (gs_fonts.ps,
    gs_res.ps)

    Updates most of the remaining pseudo-operators to take advantage of stack
    protection.  (gs_btokn.ps, gs_cmap.ps, gs_dps1.ps, gs_dps2.ps, gs_fonts.ps,
    gs_lev2.ps, gs_pdfwr.ps)

    Splits the image operators into a separate file from the path painting
    operators.  (This should have been done a long time ago.)  (iimage.h,
    zimage.c, zpaint.c)

    Adds more of the implementation of the NeXT alpha and compositing
    operations, under an #ifdef DPNEXT.  (iimage.h, zcolor1.c, zdpnext.c,
    zimage.c)

    Adds more of the implementation of DPS contexts.  These are still not
    usable.  (icontext.h, icontext.c, zcontext.c, zmath.c)

    Changes the help message to describe -dBATCH instead of -c quit.
    (imainarg.c)

    Recognizes the dictionary argument for the eexecDecode filter.  (zmisc1.c)

### Streams

    Fixes bugs:
    	- The tracing message when starting to decode 1-D fax data reported
    the run_color incorrectly.  (scfd.c)
    	- In the CCITTFaxDecode filter, if a buffer boundary fell between a
    makeup code and a final zero-length termination code, an ioerror could
    occur.  (scfd.c)
    	- Per Adobe, in the CCITTFaxDecode filter, EndOfBlock = true should
    cause Rows to be ignored.  (scfd.c)
    	- If an output stream returned EOFC, an infinite loop might result.
    This problem (and the fix) are in the same fragile code as the EOD fix in
    4.74, and we may again have introduced a new bug.  (stream.c)

    Changes the eexecDecode filter so that instead of a number, it can take a
    dictionary with two keys, seed and lenIV.  (Having eexecDecode skip initial
    bytes at all was a design bug that is too late to fix.)  (sfilter.h,
    seexec.c)

### Library

    Fixes bugs:
    	- The default mapping from RGB+alpha to RGB didn't lighten
    (premultiply) the color according to the alpha value.  (gxcmap.c)
    	- The angle error metric for rational tangent screen parameters
    should be simply the difference in angle, not a ratio.  (gshtscr.c)
    	- gs_setcolorscreen and gs_sethalftone didn't initialize an
    allocator pointer, leading to memory access errors.  (gsht1.c)
    	- If a banded image was clipped, an invalid band list could be
    produced.  (gxclimag.c)
    	- A picky compiler wouldn't allow an enum to be &&'ed with a
    boolean.  (gschar.c)
    	- A short-sighted compiler didn't allow the use of actual procedure
    names (as opposed to procedure variables) in a conditional expression.
    (gxfill.c)
    	- A compiler objected to a name longer than 31 characters.  (gzht.h,
    gsht.c, gxclread.c)
    	- The height computations for banded images were not consistent,
    possibly leading to invalid band lists.  (gxclimag.c)
    	- copypage didn't reset the band writer and band reader bookkeeping
    consistently, leading to incorrect output and possible errors.  (gxcldev.h,
    gxclist.c, gxclread.c)
    	- When banding, changing the halftone could lead to accessing memory
    after freeing it.  (gxclread.c)
    	- When using disk files for band storage, showpage didn't actually
    delete or truncate the band list file, possibly causing subsequent copypage
    operations to become confused.  (gxclfile.c)
    	- When banding, having more than one image operator in progress at a
    time confused the rasterizing pass and could produce arbitrary errors.  From
    PostScript, this can only happen in the case of an image whose data source
    was a procedure-based stream that itself invoked an image operator: this is
    a senseless and perverse thing to do, but it shouldn't break the code (and a
    Genoa CET file actually does it).  (gxclist.h, gxclimag.c, gxclist.c)
    	- Some picky compilers objected to negating unsigned values.
    (gsuid.h, gsht.c, gsmemory.c, gxpcopy.c)
    	- When banding, if a 90- or 270-degree rotated monobit image was
    clipped, invalid memory accesses could occur.  (gximage.h, gximage1.c)
    	- The showpage count passed to the BeginPage and EndPage procedures
    was incremented only if a page was printed, rather than for every invocation
    of showpage.  Fixing this requires removing the incrementing of the count
    from the library level altogether.  (gsdevice.c)
    	- When rendering a subrectangle of an image, the X DDA was
    initialized incorrectly, causing possible errors.  We think this only
    affected certain banded images.  (gxdda.h)

    Adds a provision for images with an alpha component, under an #ifdef DPNEXT.
    ****** THE BANDING CODE HAS NOT BEEN UPDATED YET. ******  (gsiparam.h,
    gxcmap.h, gxdither.h, gximage.h, gsimage.c, gxclimag.c, gxclread.c,
    gxcmap.c, gximage.c, gximage3.c, gximage4.c ****** NOT DONE YET ******,
    gximage5.c)

    Adds a return_if_error macro to capture the common idiom of making a call
    and then returning its value if that value is negative (error).  (gserror.h)

## Version 4.74 (limited) (5/5/97)

This fileset is supposed to fix all remaining errors reported by the Genoa CET, and is intended to be the last incremental test fileset before the 5.0 release.

### Documentation

    Fixes bugs:
    	- Mark procedures are *not* executed in the normal return case.
    (estack.h)
    	- The line_params element of a gs_imager_state is *not* allocated
    separately.  (gsstate.c)
    	- The value passed to the PDF writer for text is a dictionary, not
    an array.  (gdevpdft.c)

    Improves the documentation of gstate memory management.  (gsstate.c)

    Documents end_status = EOFC for writing streams.  (stream.h, strimpl.h)

    Clarifies memory management for halftones and device halftones.  (gsht1.h,
    gxdht.h, gxht.h, gzht.h)

    Removes the "experimental" tag from the PostScript and EPS writers.
    (devs.mak)

### Utilities

    Fixes bugs:
    	- The viewpcx utility scaled images improperly.  (viewpcx.ps)
    	- If a PDF file used F instead of f for filling a path, pdf2ps
    didn't output the fill operation.  (pdf_base.ps)

    Changes the ps2pdf script so that, like pdf2ps, it allows debugging
    switches.  (ps2pdf)

### Drivers

    Fixes bugs:
    	- The vgalib driver didn't clip monobit images properly.
    (gdevvglb.c)
    	- The X driver asked for exposure events to be reported, but never
    read them, causing the event queue to grow indefinitely.  (gdevxini.c)
    	- The "vector" drivers and the PDF writer didn't properly keep track
    of whether the current clipping region was the default one.  (gs_pdfwr.ps,
    gdevvec.h, gdevvec.c, gdevpdf.c, gdevpdft.c)
    	- The PDF writer had word and character spacing interchanged.
    (gdevpdft.c)
    	- The PDF writer scaled word and character spacing incorrectly.
    (gdevpdft.c)

### Interpreter

    Fixes bugs:
    	- The user object operators didn't leave the stack in a clean state
    if they failed.  (gs_dps2.ps)
    	- UserObjects wasn't actually defined.  (gs_dps2.ps)
    	- deviceinfo and set/currenthalftonephase were defined even if the
    dps feature wasn't selected.  (int.mak, gs_dps.ps, gs_dps1.ps, gs_lev2.ps,
    zdps.c, zdps1.c)
    	- The dps feature didn't automatically include the level2 feature,
    which it needs.  (int.mak)
    	- The DPS user names mechanism didn't work, since the user names
    array was subject to save and restore.  (It still doesn't really work --
    there is no provision for expanding the user names array, which is created
    with length 0.)  (gs_btokn.ps, ivmspace.h, zbseq.c, zdps.c)
    	- The DPS context operators didn't do all the necessary error
    checking.  (zcontext.c)
    	- The debugging printout for names printed the name index in hex
    without identifying it as such.  (idebug.c)
    	- Adding the first non-name key (or name key with a name index
    beyond 4K) to a dictionary that had any deleted entries could cause some
    entries to apparently disappear.  (idict.c)
    	- If a sub-table of the name table was freed during garbage
    collection, memory could be left in an inconsistent state.  (iname.c, igc.c)
    	- findfont didn't restore the stacks reliably if an error occurred.
    (gs_fonts.ps)
    	- definefont with an invalid Type 0 font sometimes added a FID entry
    (with a dangling pointer) if it failed.  (Recovering properly from a VMerror
    during font creation would require a much more complicated fix than this,
    but since we expect a garbage collection to occur in that case, we aren't
    concerned about it.)  (zfont0.c)
    	- Reading parameter values from a dictionary could access beyond the
    end of the array that keeps track of which entries had been referenced.
    (idict.h, idict.c, iparam.c)
    	- Halftone data was allocated in the current VM rather than in the
    same VM as the halftone dictionary or procedure.  (Fixing this includes
    updating code as necessary for the change in halftone and device halftone
    allocation.)  (iht.h, ivmspace.h, zht.c, zht1.c, zht2.c)
    	- Closed non-executable files on the e-stack could cause a restore
    to be invalid.  (zvmem.c)

    Adds skeleton code for the NeXT Display PostScript alpha and compositing
    operators.  This is not ready for use yet!  (errors.h, gs_dpnxt.ps,
    zdpsnext.c)

    Implements more of state saving and restoring for Display PostScript
    contexts.  This is not ready for use yet either.  (int.mak, icontext.h,
    istack.h, icontext.c, zcontext.c)

    Adds stub code for the Display PostScript view clip operators.  (gs_dps.ps,
    zdps.c)

    Removes the obsolete PPM-writing operator.  (int.mak, vms.mak, *.mak,
    zwppm.c)

    Makes the random number generator state public so it can be stored in the
    context state.  (zmath.c)

    Changes the flag for forcing global garbage collection to a run-time
    variable, for debugging.  (igc.c)

    Changes the handling of job control so that it doesn't use procedures that
    produce an execstackoverflow when being printed.  (gs_init.ps)

    Updates code as necessary for the change in reference counting.  (zcie.c,
    zcrd.c)

    Updates code as necessary for the change in off-stack gstate copying.
    (zdps1.c)

    Removes a small bit of obsolete code.  (interp.c)

### Streams

    Fixes bugs:
    	- An output stream that was not the last one in a pipeline could
    incorrectly be asked to write its EOD marker more than once.  (The fix is
    very fragile and may have introduced new bugs.)  (stream.c)

### Library

    Fixes bugs:
    	- The gx_device_halftone_release procedure was declared in two
    different header files.  (gzht.h)
    	- Off-stack copying of gstates could lead to a situation where
    different parts of a single gstate were owned by different allocators; this
    could cause them to be freed improperly, corrupting memory.  We fixed this
    partly by making the mixed ownership situation work, and partly by copying
    more of the gstate when off-stack gstates are involved.  Unfortunately, the
    fixes are subtle and may have introduced new bugs.  (gsstate.h, gsht.c,
    gsht1.c, gspcolor.c, gsstate.c)
    	- If an error occurred while creating a Pattern instance, the
    partially initialized instance structure wasn't freed.  (gspcolor.c)
    	- Halftones and device halftones didn't allocate their clones or
    their subsidiary structures with the correct allocator.  (gsht.c, gsht1.c)
    	- The error statement when allocating a reference-counted object had
    to be a control transfer.  (gsrefct.h)
    	- Copying gstates incorrectly copied the memory and saved pointers,
    and the pointer to the dash pattern.  (gsstate.c)
    	- Flatness values less than 0.5 produced far more line segments than
    necessary (roughly the square of the required number).  Fixing this may have
    bad effects on character quality -- this remains to be seen.  (gxpflat.c)
    	- An error during installation of a halftone could leave things in
    an inconsistent state.  (gsht.c)
    	- The API didn't provide enough flexibility with respect to memory
    management for halftones, or guarantee consistent allocation of a halftone
    and its subelements.  (gsht1.h, gsht.c, gsht1.c, gshtscr.c)
    	- Releasing a path didn't clear enough pointers to ensure clean
    garbage collection.  (gxpath.c)
    	- Finalizing or discarding a (cached) scaled font didn't properly
    unlink it from the scaled_fonts list.  (gsfont.c)
    	- Invoking an image operator within the BuildChar procedure for a
    charpath caused an infinite loop.  (gsimage.c)
    	- The bookkeeping for the scaled font cache was incorrect: the count
    didn't always get decremented when a scaled font was freed.  (gsfont.c)
    	- "High level" masked images were written incorrectly in the band
    list as black-and-white images.  (gxclimag.c)
    	- For "high level" images with fewer than 4 samples per pixel,
    non-standard Decode values were written incorrectly in the band list.
    (gxclimag.c)
    	- The color wasn't set correctly for "high level" masked images.
    (gxclimag.c)
    	- The fastest case of monobit image rendering could get a memory
    access error if the image lay partly outside the page.  (gximage1.c)
    	- Clipping with an empty path was a no-op, rather than clipping out
    everything.  (gxcpath.c)

    Makes reference-counted objects remember which allocator owns them: this
    entails a NON-BACKWARD-COMPATIBLE change to some of the macros for reference
    counting.  This was necessary to fix the off-stack gstate copying problem.
    (gsrefct.h, gscie.c, gscolor.c, gscolor1.c, gscolor2.c, gscsepr.c,
    gsstate.c, gxclread.c)

    Refactors the unpacking of image data, to make unpacking available as a
    general facility.  (gximage.h, gxsample.h, gximage.c, gximage0.c,
    gximage1.c, gximage4.c, gxsample.c)

    Enhances -Z? so that before freeing an object, it checks that the object was
    owned by the correct allocator.  (gsalloc.c)

## Version 4.73 (limited) (4/19/97)

This is an incremental bug fix release made primarily to provide a synchronization point for an upcoming trip.

### Documentation

    Fixes bugs:
    	- A reference to the uniprint documentation was incorrect.
    (current.txt)
    	- -Olimit 1000 is not enough now for DEC Ultrix, 1200 is required;
    this is also required for SGI IRIX.  (make.txt)

    Adds argument/result comments to all the operators defined in gs_lev2.ps.
    (Eventually we will do this for all operators defined as PostScript
    procedures.)  (gs_lev2.ps)

### Procedures

    Fixes bugs:
    	- The makefiles didn't provide a default value for GCONFIG_EXTRAS.
    (gs.mak)

### Utilities

    Fixes bugs:
    	- pdf2ps didn't work with TrueType or compressed Type 1 fonts.
    (gs_pdf.ps, pdf_2ps.ps, pdf_font.ps)

### Drivers

    Fixes bugs:
    	- A cast from byte to char was omitted.  (gdevpdfm.c)

### Platforms

    Updates the VMS script (again).  (vms.mak)

### Interpreter

    Fixes bugs:
    	- A module that used strlen didn't include string_.h.  (zdevice.c)
    	- Because of some bad PostScript code in FrameMaker output, identity
    rather than unity black generation and undercolor removal functions are
    required on black-and-white devices.  (gs_init.ps)
    	- A harmless internal error during initialization left bogus
    information in $error.  (gs_cidfn.ps)
    	- startjob didn't clear the execution stack.  Fixing this required
    NON-BACKWARD-COMPATIBLE changes to the internal operators .instopped, .stop,
    and .stopped, which are not supposed to be used by any external code.
    (startjob will still give errors if executed in a file that isn't being
    piped from stdin; this will take longer to fix.)  (gs_init.ps, gs_lev2.ps,
    iref.h, imain.c, interp.c, zcontrol.c, zfile.c)

    Adds a new .execn operator, part of the startjob changes, that allows
    pushing multiple items on the exec stack.  Eventually this will allow us to
    get rid of many dynamically created closures.  (zcontrol.c)

### Interpreter (PDF)

    Fixes bugs:
    	- Landscape-mode PDF files weren't rotated properly.  (gs_pdf.ps,
    pdf_main.ps)

    Makes the default PDF configuration notify users more informatively when
    encountering an encrypted file.  (pdf_sec.ps)

### Streams

    Makes the RunLengthEncode filter always generate optimally compressed
    output.  We did this because we thought one of the Genoa CET files loops
    forever if this is not the case; but we were wrong.  (srle.c)

### Library

    Fixes bugs:
    	- If one coordinate of a position or distance overflowed the
    internal representable range, the other coordinate became garbage.  (bug
    introduced in 4.70) (gspath.c)
    	- The bounding box computation for strokes was slightly too large
    (sometimes much too large).  (gxpaint.h, gdevbbox.c, gxclpath.c, gxstroke.c)

    Adds (under an #if 0) an experimental alternate halftone cell choice
    algorithm.  (gshtscr.c)

    Adds a better comment to a particularly obscure line of C code.
    (gxclimag.c)

## Version 4.72 (limited) (4/14/97)

This is another bug fix release, motivated mostly by Genoa testing. It also updates the new uniprint driver with a major revision, and upgrades CFF support a little bit.

### Documentation

    Fixes bugs:
    	- -dNOGC only disables default automatic garbage collection, not all
    garbage collection.  (use.txt)
    	- Apparently a different set of flags is needed for newer H-P
    compilers.  (make.txt)

    Replaces the tiny FAQ with a pointer to the on-line FAQ.  (use.txt)

    Updates the documentation for the uniprint driver.  (devices.txt)

    Clarifies the fact that Ghostscript reads Fontmap files from *all*
    directories in the search list.  (use.txt)

    Notes that building on Linux may require SM and ICE in the list of X
    libraries.  (make.txt)

### Procedures

    Fixes bugs:
    	- An -include type42 was omitted from the level2 module description.
    (int.mak)
    	- A mention of $(ECHOGS) in the rule for sfile should have been
    $(ECHOGS_XE).  (lib.mak)
    	- The pcx2up sample device should have been put in devs.mak rather
    than lib.mak.  (devs.mak, lib.mak)
    	- scanchar.h and scantab.c belong in the library, not the
    interpreter.  (devs.mak, int.mak, lib.mak)
    	- Some _h definitions were used before being defined, or weren't
    defined at all.  (devs.mak, lib.mak)
    	- The JPEG driver was missing a dependency.  (devs.mak)
    	- The PDF writer was missing a dependency.  (devs.mak)
    	- Building Level 1 systems was no longer possible.  (int.mak)

    Updates the VMS build scripts.  (vms.mak, vms-decc.mak)

    Adds *.upp to the list of files installed under Unix.  (unix-end.mak)

    Adds rules to the Unix makefiles to build two library files: gs.a,
    consisting of the entire PostScript/PDF interpreter lacking only gs.c, and
    gslib.a, consisting of the graphics library without the gslib.c test driver.
    (ansihead.mak, cc-head.mak, gcc-head.mak, unixtail.mak)

### Drivers

    Fixes bugs:
    	- The PS/EPS writers could generate a reference to an undefined
    name.  (gdevps.c)
    	- The PDF writer produced incorrect output for multi-level outlines.
    (gdevpdfm.c)
    	- The PDF writer didn't convert /Action to /A, and /Action/Subtype
    to /S, in Annot dictionaries.  (gdevpdfm.c)
    	- The PDF writer didn't work in Level 1 systems.  (gs_pdfwr.ps)
    	- The PDF writer didn't transform /Rect and /R values to current
    user coordinates.  (gs_pdfwr.ps, gdevpdfx.h, gdevpdfm.c)
    	- The PNG writer could refer to the 3 predefined stdio files even in
    environments where this was undesirable.  (gdevpng.c)
    	- The PDF writer had a compiled-in limit of 100 pages of output.
    (gdevpdfx.h, gdevpdf.c)

    Updates the uniprint driver with a major revision that uses device
    parameters that can be set from the command line, rather than PostScript
    code, for configuration choices.  (gdevupd.c, *.upp)

### Platforms

    Fixes bugs:
    	- gp_enumerate_files_next had no way to return an error.  (gp.h,
    gp_dosfe.c, gp_ntfs.c, gp_os2.c, gp_unifs.c, gp_vms.c) ****** NOT
    IMPLEMENTED YET ******
    	- On the Watcom platform, CPU_TYPE >= 486 didn't automatically set
    FPU_TYPE to 387.  (wccommon.mak)

### Interpreter

    Fixes bugs:
    	- Caching the current device in userdict could create dangling
    references.  (gs_init.ps, gs_pdfwr.ps, zdevice.c)
    	- If an error occurred in a BuildChar or BuildGlyph procedure, the
    graphics state stack wasn't restored.  (ichar.h, zchar.c, zchar2.c)
    	- There was an obsolete check for a structure when cleaning up after
    a show operator.  (zchar.c)
    	- Attempting to show a character with no associated glyph in a Type
    3 font with a BuildGlyph procedure caused an error.  (zchar.c)
    	- noaccess on a read-only dictionary didn't give an error.
    (ztype.c)
    	- The dictionary passed to a Pattern's PaintProc was the original
    template, not the copy made by makepattern.  (gs_lev2.ps)
    	- Invalid font parameters could result in partially constructed
    fonts, which caused problems for restore.  (zfont0.c, zfont2.c)
    	- Files run under job control caused an error when terminating.
    (gs_init.ps)
    	- setpagedevice didn't protect itself against malfunctioning
    BeginPage or EndPage procedures.  (The protection is still not perfect.)
    (gs_setpd.ps)
    	- .type42execchar called font_param redundantly.  (zchar42.c)
    	- The font operators didn't protect themselves well enough against
    bogus font dictionaries.  (zfont.c, zfont0.c)
    	- If an error occurred within a stringwidth, the graphics state
    stack wasn't restored properly.  (zchar.c)
    	- If an error occurred within the PaintProc of a form, the graphics
    state stack was left with an extra entry.  (gs_lev2.ps)
    	- Registering a font under a second name could corrupt data
    structures.  (zfont2.c)
    	- Different scalings of the same font should have "equal" fontIDs,
    to match the Adobe implementations.  (iutil.c)
    	- Errors detected by PostScript code during initialization either
    allowed execution to continue or produced a hex stack dump, instead of just
    producing a message and exiting.  (interp.c)
    	- The memory validator didn't validate chunks at previous save
    levels.  (ilocate.c)
    	- The Level 1 size of systemdict was too small.  (iinit.c)
    	- Attempting to define a Category resource in local VM gave a
    typecheck error rather than an invalidaccess.  (gs_res.ps)
    	- Building Level 1 systems was no longer possible.  (zusparam.c)

    Rearranges the interpreter code slightly so that all operator invocations go
    through a single procedure when debugging.  (interp.c)

    Adds a -K<numK> switch to limit the total amount of memory that Ghostscript
    can acquire.  (imainarg.c)

    Makes the memory validator check packed refs more carefully.  (ilocate.c)

    Makes the memory validator check explicitly for pointers to freed objects.
    (igc.c, ilocate.c)

    Makes the memory validator check dictionaries more carefully.  (ilocate.c)

    Makes the memory validator check refs embedded in structures.  (ilocate.c)

    Adds a debugging option that bypasses the garbage collector entirely.
    (igc.c)

    Adds debugging options to validate memory before/after save/restore.
    (zvmem.c)

    Removes the patch for the uniprint driver, since it is no longer needed.
    (gs_init.ps)

    Implements real-number operands in CFF fonts.  (gs_cff.ps)

    Implements non-default charsets in CFF fonts.  (gs_cff.ps)

### Interpreter (PDF)

    Fixes bugs:
    	- The PDF 1.2 "marked content" operators weren't defined.
    (pdf_main.ps)
    	- Streams with binary data whose first character was an EOL (\n)
    didn't parse properly.  Unfortunately, the way we fixed this may break some
    other files.  (pdf_base.ps)
    	- PDF 1.2 #nn escape syntax in names wasn't recognized.  ****** This
    is implemented with an inefficient hack that should be moved down into C.
    However, I don't want to risk introducing new bugs during the beta test
    period. ****** (pdf_base.ps)
    	- The interpreter had a limit of 64K objects.  Removing this limit
    required changing a basic data structure -- admittedly a risky thing to do
    during beta test.  (pdf_base.ps, pdf_main.ps)
    	- TJ didn't multiply the offsets by the font size, causing incorrect
    character positioning.  (gs_pdf.ps)

### Streams

    Fixes bugs:
    	- The ASCIIHexDecode filter read an extra character in case of
    error.  (sstring.c)

    Adds more tracing output to the CCITTFaxDecode stream.  (scfd.c)

### Library

    Fixes bugs:
    	- The allocator client name for rendering bitmap patterns was
    incorrect.  (Only affects tracing output.)  (gspcolor.c)
    	- The check for exceeding the overall allocation limit was
    incorrect, because of unsigned arithmetic.  (Only affects limitation of
    total allocation, which is only used for debugging and benchmarking.)
    (gsmemory.c)
    	- The 0'th component of colored screens wasn't passed through the
    band list, possibly causing access errors when rasterizing.  (gxclimag.c,
    gxclread.c)
    	- setbbox could get an overflow without detecting it.  (gsdps1.c)
    	- Images with only one component but MultipleDataSources = true
    could cause a memory access error.  (gximage.c)
    	- The buffer for unpacking 12-bit-per-sample image data was too
    small, causing memory corruption.  (gximage.c)
    	- 12-bit-per-sample images with multiple data sources sometimes
    didn't pass correct pointers to image_data.  (gsimage.c)
    	- If an image data stream reached EOF before supplying enough data
    for the entire image, memory corruption could occur.  (zpaint.c)
    	- When a device halftone was freed, some pointers in the halftone
    cache weren't cleared, leading to possible dangling references.  (gsstate.c)
    	- Invalid font parameters could result in partially constructed
    fonts, which caused problems for restore.  (gxfont0.h, gsfont.c)
    	- If an error occurred within a stringwidth, the graphics state
    stack wasn't restored properly.  (gschar.c)
    	- The (static) limit on the size of a command line argument was too
    small.  (gsargs.h)
    	- Building Level 1 systems was no longer possible.  (gxdht.h,
    gsht.c, gsht1.c)
    	- Truncation instead of rounding caused colors on gray-scale devices
    to come out very slightly too dark.  (gxcmap.c)
    	- The Decode mapping table constructed for images was slightly
    inaccurate for ranges other than [0 1] or [1 0].  (gximage.c)

## Version 4.71 (limited) (3/31/97)

This is a bug fix release during the beta test period.

### Documentation

    Fixes bugs:
    	- A larger value of -Olimit is now needed to optimize gxclread.c.
    (make.txt)
    	- Some comments were incorrect.  (gdevbbox.h, sfilter1.c)

    Updates the GPL with a newer version from FSF.  (COPYLEFT)

    Notes that the gcc 2.7.x code generation bug is fixed in 2.7.2.1.
    (make.txt)

### Procedures

    Fixes bugs:
    	- Some streams required by high-level drivers were incorrectly
    grouped with the interpreter rather than the library.  (int.mak, lib.mak)
    	- The choice of implementation for file streams was buried in an
    obscure place, rather than being included in the configuration definitions
    at the head of each makefile.  (We believe there are no more such buried
    parameters.)  This involved a NON-BACKWARD-COMPATIBLE change in the way this
    choice was specified.  (lib.mak, *.mak)
    	- Some dependencies were missing.  (lib.mak)

### Drivers

    Fixes bugs:
    	- A variable was used before being initialized, causing get_bits
    (and raster ops) to fail when using alternate X devices.  (bug introduced in
    4.70.)  (gdevxalt.c)
    	- Some 'private' declarations were omitted.  (It is infuriating that
    gcc doesn't check for this!)  (gdevps.c, gdevpx.c)
    	- A few character strings were used as byte arrays without a cast.
    (gdevpx.c)
    	- The EPS writer didn't write a correct bounding box, and didn't
    write it at the beginning of the file.  (gdevvec.h, gsstruct.h, gdevps.c,
    gdevvec.c)
    	- x_copy_color specified an incorrect (too large) image width.
    Apparently this only mattered because it could cause invalid memory
    accesses.  (gdevx.c)
    	- x_copy_mono also specified too large an image width.  It's not
    clear this made any difference.  (gdevx.c)
    	- The default implementation of strip_copy_rop didn't clamp Y values
    to legal values for get_bits.  (gdevmrop.c)

### Interpreter

    Fixes bugs:
    	- Some initialization files prematurely switched the interpreter
    into Level 2 mode, causing some Level 2 operators not to be defined.  (bug
    introduced in 4.60 or later.)  (gs_cff.ps, gs_cidfn.ps, gs_cmap.ps,
    gs_init.ps, gs_res.ps)

### Streams

    Fixes bugs:
    	- The choice of procedure names for the file-descriptor-based
    implementation of file streams was buried in a .c file, rather than being
    chosen in the makefile.  (sfile.c[deleted], sfileno.c[deleted], sfxstdio.c,
    sfxfd.c, sfxboth.c)

### Library

    Fixes bugs:
    	- rcurveto was broken -- it drew curves to random points.  (bug
    introduced in 4.61.)  (gspath.c)
    	- A trailing comma in an enum definition upset some compilers.  (bug
    introduced in 4.70.)  (gstype1.h)
    	- Type 1 fonts with hint replacement could produce anomalous or
    clipped output, or even missing lines.  (Also cleans up some out-of-date
    formatting.)  (gxtype1.h, gstype1.c, gxhint2.c)
    	- Removes some conditionals for choosing between old and new
    algorithms.  (gxhint3.c)
    	- makebitmappattern required that the bitmap consist of only a
    single tile repetition.  (gspcolor.c)
    	- Some computations on RasterOps didn't take transparency into
    account properly.  (gdevmrop.c)
    	- The structure definition for imager and graphics states had an
    incorrect offset for line_params, causing the garbage collector not to mark
    or relocate dash patterns, possibly causing memory faults, FPEs, or invalid
    output.  (bug introduced since 4.03.)  (gsstate.c)
    	- 'show' operators gave a limitcheck for unreasonable coordinates,
    even if limit clamping was enabled.  (gschar.c)

    Implements banded filling and stroking with colored halftones, in addition
    to pure colors and binary halftones.  Since we are in a beta test period,
    actual use of this feature (but *not* all the code implementing it) is
    disabled under an #ifdef FUTURE.  (gsdcolor.h, gxcldev.h, gxclpath.h,
    gxdht.h, gxhttype.h, gsht.c, gxclimag.c, gxclpath.c, gxclread.c)

## Version 4.70 (limited) (3/26/97)

This fileset fixes the one outstanding compilation problem on PC platforms and the old problem of limitchecks for out-of-bounds coordinates, and adds a variety of new features, including the ability to save away the band lists for pages and rasterize them later and/or elsewhere in any order and combination. This is the first "serious beta" candidate for the next general release.

Fileset numbers 4.62 through 4.69 were skipped deliberately.

### Documentation

    Fixes bugs:
    	- The list of special -d and -s switches was out of date.  (use.txt)
    	- The name of the zlibDecode filter was incorrectly written
    zlibEncode.  (language.txt)

    Documents where to find out how to install gcc 2.7.x on SGI IRIX 6.x.
    (make.txt)

    Documents a makefile patch required on NeXTStep.  (make.txt)

    Documents how to patch gcc to fix the AXP code generation bug.  (make.txt)

    Adds documentation for the new unified printer driver.  (devices.txt)

### Procedures

    Fixes bugs:
    	- 'make distclean' didn't remove a couple of files.  (gs.mak)
    	- A library module didn't include a necessary dependency.  (lib.mak)
    	- A new .ps file wasn't installed properly.  (unix-end.mak)
    	- File write dates weren't updated properly on PC platforms, causing
    unnecessary rebuilding.  (cp.bat, gs.mak, msc.mak, msvcwint.mak, os2.mak,
    tccommon.mak, wccommon.mak, zlib.mak)
    	- An unnecessary explicit compilation line for gdevcdj.c caused
    problems in the Mac environment.  (devs.mak)
    	- The VMS scripts were out of sync again.  (vms.mak)
    	- The VMS build scripts didn't include the new JPEG driver.
    (vms-*.mak)
    	- A number of makefile macros were referenced before being defined.
    (devs.mak, lib.mak, int.mak, *.mak)
    	- libpng.mak didn't work with PVERSION=90.  (libpng.mak, zlib.mak)

    Separates install-scripts from install-exec and install-data.
    (unix-end.mak)

    Moves the definition of SEARCH_HERE_FIRST from iminst.h to the makefiles.
    (*.mak, iminst.h, iconf.c, imain.c)

    Adds a -dBATCH switch that causes Ghostscript to exit after processing the
    files named on the command line.  (gs_init.ps)

    Adds the PostScript, EPS, and PCL XL writers, and the color and gray-scale
    JPEG drivers, to all Unix configurations.  (ansihead.mak, cc-head.mak,
    gcc-head.mak)

### Drivers

    NOTE: because of a change in an internal interface (clist_output_page), the
    cp50 driver no longer works.  This is a user-contributed driver for which we
    take no responsibility.

    Fixes bugs:
    	- gdevcdj.c wasn't compatible with ansi2knr.  (gdevcdj.c)
    	- 'private' was omitted from some declarations.  (gdevjpeg.c)
    	- The PostScript writer didn't keep track of the current color
    properly.  (gdevps.c)
    	- RESOLUTION was misspelled in a header.  (gdevbjc.h)
    	- Some compilers objected to the use of a floating point initial
    resolution value.  (gdevbjc.h)
    	- Some compilers didn't allow static initialization of a union.
    (gsdcolor.h)
    	- If a TIFF driver got an error when initializing the CCITTFax
    encoder, it returned a bogus error code.  (gdevtfax.c)
    	- The PDF writer produced incorrect output for Indexed color space
    images.  (gdevpdfi.c)
    	- For many fatal error conditions, the X driver called exit()
    instead of returning an error.  (gdevx*.c)

    Adds new drivers:
    	- epswrite, an EPS-writing driver (instead of making EPS output a
    parametric option of the PostScript-writing device).  (devs.mak, gdevps.c)
    	- pcxcmyk, a 4-bit CMYK PCX driver.  This is probably only useful
    for debugging CMYK color rendering.  (gdevpcx.c)
    	- jpeggray, a JPEG driver that produces gray-scale rather than color
    output.  Thanks to Tom Lane for contributing this.  (gdevjpeg.c)
    	- uniprint, a unified printer driver for a wide variety of inkjet
    printers.  Thanks to Gunther Hess for contributing this.  (gdevupd.c)

    Adds the resolution (pHYs) to the output of the PNG drivers.  (gdevpng.c)

    Adds recognition of the ASCII85EncodePages parameter to the PostScript and
    EPS writers.  (gdevps.c)

    Makes the new JPEG driver write a JFIF header, which contains the image
    resolution.  (gdevjpeg.c)

    Changes the "vector" device support interface so relative movement can be
    detected easily.  THIS IS STILL SUBJECT TO CHANGE WITHOUT NOTICE.
    (gdevvec.h, gdevpsdf.c, gdevps.c, gdevpx.c, gdevvec.c)

    Changes the PostScript, EPS, and PDF writers to recognize curves and lines
    that can be represented more efficiently.  (gdevpsdf.h, gdevpsdf.c,
    gdevps.c)

    Adds a new parameter to the PDF writer, FirstObjectNumber.  This defines the
    first object number that will be used in the output.  The default, and
    minimum, value is 1; the maximum value is approximately 2^31.  This is for
    the benefit of dvipdf; we don't expect it to be used otherwise.  In fact,
    using it appears to produce files that Adobe Acrobat Reader won't accept,
    even though the files are perfectly compliant with the published PDF
    specification.  (gdevpdfx.h, gdevpdf.c, gdevpdfp.c)

### Platforms

    Removes the makefile for the 16-bit Borland C++ platform.  This was the last
    supported 16-bit platform; we expect to gradually drop all 16-bit
    concessions from the code itself.  (bcwin.mak)

### Interpreter

    Fixes bugs:
    	- The initial size of systemdict was too small, causing the
    interpreter to slow down substantially.  (iinit.c)
    	- A library module depended on an interpreter module.  (zcsindex.c)
    	- A logically necessary (but accidentally always available) #include
    was missing.  (ifont.h)

    Moves set/currentoverprint to a more appropriate module.  (zcolor2.c,
    zcssepr.c)

    Changes the default transfer functions so that they do something reasonable
    when given operands outside the legal [0..1] range.  We only do this to work
    around a bug in FrameMaker output, which uses the transfer function as the
    screen function (!).  (gs_init.ps)

    Changes the CMap construction algorithm to use the new, more compact
    representation.  (zfcmap.c)

    Adds support for Adobe's Compact Font Format.  Many individual features are
    not implemented yet: see the comment in the source code for details.
    (gs_cff.ps)

    Adds support for Type 2 charstrings in Type 1 fonts.  (ifont.h, zfont1.c)

    Changes the Type 1 character rendering operator for the library change in
    Type 1 fonts.  (zchar1.c, zfont1.c)

    Initializes the graphics state limit clamp flag to true.  (zgstate.c)

    Temporarily adds a configuration file for the new unified printer driver,
    and arranges for it to be read at startup.  This arrangement will be
    replaced very soon by a different one based on command line parameters.
    (gs_init.ps, uniprint.ps)

### Interpreter (PDF)

    Adds support for Compact Font Format fonts.  (pdf_font.ps)

### Streams

    Adds a glue procedure needed for the new jpeggray driver.  (sjpeg.h,
    sjpege.c)

    Removes the width limit of 32K in the CCITTFaxEncode filter.  The new limit
    is absurdly large (about 50M).  (scf.h, scfx.h, scfe.c)

### Library

    Fixes bugs:
    	- A library module depended on an interpreter module.  (gxcolor2.h,
    gscolor2.c)
    	- When rendering a band, clipping was sometimes used when it wasn't
    necessary.  (Performance only.)  (gxclread.c)
    	- Stroking didn't check the path against the device clipping box in
    the absence of an explicit (non-default) clipping path.  (Performance only.)
    (gxstroke.c)
    	- A reference to an opaque type upset a couple of compilers.
    (gxclread.c)
    	- Negative 32-bit numbers in Type 1 fonts didn't work properly on
    64-bit systems.  (gstype1.c)
    	- A logically necessary (but accidentally always available) #include
    was missing.  (gxbitmap.h)
    	- A header wasn't protected against double inclusion.  (gxclist.h)
    	- Clipping devices didn't store their actual width and height.
    (gxcpath.c)
    	- The slow-case check for thin lines was incorrect.  (gxstroke.c)
    	- Images didn't compute their clipping boxes correctly if there
    wasn't an explicit clipping path.  (This must be a very recent bug, since it
    creates an overflow condition that prevents monochrome images from being
    rendered at all.)  (gximage.c)

    Moves set/currentoverprint to a more appropriate module.  For clients of
    gs_set/currentoverprint, this is a NON-BACKWARD-COMPATIBLE CHANGE, since the
    header file is now separate.  (gscolor2.h, gscsepr.h, gscolor2.c, gscsepr.c)

    Replace the MetroWerks work-around with a different, more general one.
    (gdevmem.h, gdevmem.c, gxdevice.h)

    Speeds up the Type 1 interpreter a little.  (gstype1.c, gxhint3.c)

    Redesigns the internal representation of CMaps to be more space-efficient.
    (gxfcmap.h, gschar0.c, gsfcmap.c)

    Implements a facility for saving away pages and rendering them later.
    Currently this requires the pages to be represented as band lists on files,
    and only allows X translation when rendering.  This involves adding the
    following new printer device parameters:
    	BandHeight
    	BandWidth
    	BandBufferSpace
    Also changes the names of the printer device parameter elements from
    use_buffer_space to BufferSpace and from max_bitmap to MaxBitmap for
    consistency.  (gdevprn.h, gxcldev.h, gxclio.h, gxclist.h, gxclmem.h,
    gxclpage.h, gxdevmem.h, gdevmem.c, gdevp2up.c, gdevprn.c, gxclmem.c,
    gxclpath.c, gxclread.c)

    Changes the band list implementation API to allow closing a file without
    deleting it, and to allow reopening an existing file.  This is a
    NON-BACKWARD-COMPATIBLE change to a deep internal interface.  (gxclio.h,
    gxclmem.h, gxclfile.c, gxclist.c, gxclmem.c)

    Speeds up rendering of colored halftones, by recognizing cases where one or
    more planes don't actually require screening, unrolling a loop, and doing
    basic clipping before halftoning.  (gxcht.c)

    Adds a graphics state parameter, gs_set/currentlimitclamp, that changes the
    handling of out-of-range coordinates to clamp them in a way that produces
    approximately the intended output most of the time, rather than causing a
    limitcheck.  Currently this is only designed to work with the basic path
    construction operations ([r]moveto, [r]lineto, [r]curveto, closepath); it
    does not work with many other operations such as show, flattenpath or the
    rectangle operations.  Note also that while currentpoint will return the
    correct (unclamped) value, reading out the path with pathforall will return
    clamped values.  This involves NON-BACKWARD-COMPATIBLE changes to the path
    structure (but not to any public interfaces).  (gxpath.h, gxtype1.h,
    gzpath.h, gzstate.h, gspath.c, gspath1.c, gsstate.c, gstype1.c, gxpaint.c,
    gxpath.c, gxpath2.c, gxpcopy.c)

    Adds support for Type 2 charstrings.  Some features are not implemented yet:
    see gstype2.c for details.  (gscrypt1.h, gstype1.h, gxfont1.h, gxop1.h,
    gxtype1.h, gstype1.c, gstype2.c, gxhint2.c, gxhint3.c, gxtype1.c)

## Version 4.61 (limited) (3/13/97)

This fileset cleans up many compiler warnings. It adds support for CMap-encoded fonts, and a driver that writes JPEG images.

### Documentation

    Corrects an error in the description of the internal CodeMap structure.
    (gs_cmap.ps)

    Documents the fact that the optimizer in gcc 2.7.2.1 is broken on AXP
    machines.  (make.txt)

    Corrects the name of the .setglobal/.currentglobal procedures.  (zvmem2.c)

    Updates current.txt in preparation for the release.  (current.txt)

### Procedures

    Fixes bugs:
    	- The VMS script was out of date again.  (vms.mak)
    	- CIDFont support unnecessarily required composite font support.
    (int.mak)
    	- CMap and CIDFont support had improper dependencies on
    initialization order.  (lib.mak, int.mak)
    	- Some dependencies were missing in the JPEG library code.
    (jpeg.mak)

    Adds the new JPEG driver to all standard configurations.  (*.mak)

### Drivers

    Fixes bugs:
    	- A dependency was omitted from the makefile.  (devs.mak, gdevps.c)

    Cleans up some warnings from picky compilers.  Some of these actually
    indicated problems, such as unreachable code.  (gdevpdfx.h, gdevbj10.c,
    gdevcdj.c, gdevpdfp.c, gdevstc.c)

    Adds a JPEG-writing driver.  Currently this only produces RGB output and
    only has a QFactor parameter, but eventually it could take all the other
    parameters of the DCTEncode filter.  (devs.mak, int.mak, lib.mak,
    gdevjpeg.c)

    Refactors the PDF and PostScript output drivers so that both of them
    understand all the relevant documented PDF distiller parameters.  (The
    PostScript driver currently disregards nearly all of them.)  (gdevpdfx.h,
    gdevpsdf.h, gdevvec.h, gdevpdf*.c, gdevps.c, gdevpsdf.c, gdevpx.c)

### Platforms

    Fixes bugs:
    	- The MetroWerks C compiler gave an inexplicable error on a
    particular initialization.  (gdevmem.h, gdevmem.c)

### Interpreter

    Fixes bugs:
    	- The insideness testing operators sometimes reported hits
    incorrectly.  (zupath.c)
    	- Mixed-type arithmetic used floats rather than doubles when
    converting integers, possibly leading to loss of precision.  (zarith.c,
    zrelbit.c)
    	- composefont was defined in a private dictionary, not in
    systemdict.  (gs_cmap.ps)
    	- composefont didn't work, for several different reasons.
    (gs_cmap.ps)
    	- After a Type 1 font called an OtherSubr, an invalid memory access
    usually occurred, because of an incorrect attempt to free a data structure.
    (zchar1.c)
    	- 2 .setlanguagelevel gave an error if globaldict hadn't been
    defined yet.  (zmisc2.c)

    Cleans up some warnings from picky compilers.  Some of these actually
    indicated problems, such as unreachable code, or failure to check for
    (implausible) out-of-range data.  (idict.c, idparam.c, igc.c, iinit.c,
    imain.c, iscan.c, zbseq.c, zchar1.c, zdps1.c)

    Adjusts clients for a change in the internal character cache structure and
    the introduction of the font next-glyph procedure.  (zfont.c, zfont0.c)

    Refactors the Level 1 / Level 2 interpreter split slightly so that composite
    fonts don't require all of Level 2.  (int.mak, gs_dps1.ps, gs_dps2.ps)

    Adds FMapType 9 (CMap-encoded) composite font support.  (int.mak,
    gs_cmap.ps, ifont.h, zfcmap.c, zfont.c, zfont0.c)

### Interpreter (PDF)

    Adds recognition of /Identity values for BG, UCR, and TR functions in
    ExtGState resources.  (General function values still aren't recognized.)
    (pdf_draw.ps)

    Centralizes the handling of inherited attributes.  (pdf_draw.ps,
    pdf_main.ps)

    Starts to add support for Type 0 fonts.  (pdf_font.ps, pdf_main.ps)

### Streams

    Cleans up some warnings from picky compilers.  Some of these actually
    indicated problems, such as unreachable code.  (shc.h, scfd.c, sfilter2.c,
    siscale.c, stream.c)

### Library

    Fixes bugs:
    	- Some picky compilers disliked certain conditional expressions.
    (gxclread.c)
    	- Some picky compilers couldn't handle an extraneous semicolon.
    (gdevvec.h)
    	- A cast from byte ** to const byte ** was missing.  (gdevvec.c)
    	- Resizing the levels array of a halftone order when banding could
    cause invalid memory accesses.  (bug introduced in 4.60) (gxclread.c)
    	- One picky compiler didn't allow taking the address of an extern
    undefined structure.  (lib.mak, gxclread.c)
    	- When rendering Type 1 fonts, character overshoot was usually
    suppressed when it shouldn't have been, often producing "squashed"
    characters.  (gxhint1.c)
    	- On systems where sizeof(long) > sizeof(int), coordinate values of
    more than 22 bits were passed through the band list incorrectly, producing
    incorrect output.  (gxclread.c)

    Cleans up some warnings from picky compilers.  Some of these actually
    indicated problems, such as unreachable code or (hypothetical) loss of
    precision.  (gsdevice.c, gshsb.c, gsht.c, gsstate.c, gstype1.c, gxclimag.c,
    gxclpath.c, gxclread.c, gxpdash.c)

    Makes using font hints conditional, for debugging.  (gxhint1.c)

    Adds library-level support for FMapType 9 (CMap-encoded) composite fonts.
    There is still no support for rearranged fonts.  (gsccode.h, gsfcmap.h,
    gsstruct.h, gxfcache.h, gxfcmap.h, gxfont.h, gxfont0.h, gschar.c, gschar0.c,
    gsfcmap.c, gsfont.c, gsfont0.c)

    Splits band list control and utilities from rectangle-oriented commands,
    because a file was getting too big.  (gxclist.c, gxclrect.c)

    Moves the temporary file names for command lists from the printer device
    structure to the command list structure; moves opening and closing the
    temporary files from gdev_prn_alloc/free to clist_open/close.  (gdevprn.h,
    gxclist.h, gdevprn.c, gxclist.c, gxclread.c)

    Changes the command list storage implementation interface to pass the file
    name to the clist_rewind and clist_fseek functions, for the benefit of OSs
    that require closing and reopening a file to switch between reading and
    writing.  This is a NON-BACKWARD-COMPATIBLE change in a non-public
    interface.  (gxclio.h, gxclmem.h, gxclfile.c, gxclist.c, gxclmem.c)

    Changes the get_outline procedure in Type 42 fonts to return the length of
    the outline data as well as the pointer.  This is a NON-BACKWARD-COMPATIBLE
    change in a semi-public interface.  (gxfont42.h, gstype42.c)

## Version 4.60 (limited) (3/2/97)

This fileset moves color rendering up from the graphics state to the imager state so that color rendering can happen after banding. It also shifts image rendering to the rendering pass of banding for many common cases (often referred to inaccurately as "high-level image" capability). The changes involved are substantial and in some respects subtle, so unfortunately it is quite possible that some new bugs have been introduced.

This fileset also includes improvements to the new PCL XL driver (pxlmono/color), and introduces an experimental PostScript driver (pswrite).

### Documentation

    Fixes bugs:
    	- The argument list of colorimage was incorrect.  (zcolor1.c)
    	- false .charboxpath incorrectly claimed to create the correct path
    even when the CTM was not well-behaved.  (language.txt)
    	- The discussion of the "main program" files was out of date.
    (make.txt)

    Updates the OS/2 EMX documentation.  (make.txt)

    Modifies the Aladdin Ghostscript Free Public License slightly so it may be
    applied to other software packages.  (PUBLIC)

    Updates inaccurate build documentation for several Unix platforms.
    (make.txt, ansihead.mak, cc-head.mak, gcc-head.mak, libpng.mak)

    Notes a problem with the MIPSpro 7.1 compiler.  (make.txt)

### Procedures

    Fixes bugs:
    	- Most makefiles didn't include version.mak.  (msc.mak,
    msvcwint.mak, os2.mak, tctail.mak, wctail.mak)
    	- There was an incorrect dependency for the Windows printer device.
    (devs.mak)

    Moves the PDF writer to devs.mak.  (devs.mak, int.mak)

    Updates the main VMS script to be structured like version.mak.  (vms.mak)

### Drivers

    Factors out the stream-writing procedures from the PDF writer, so they can
    be shared with the new PostScript writer.  (gdevpdfs.h => gdevpstr.h,
    gdevpdfx.h, gdevpsdf.h, gdevpdf.c, gdevpdfi.c, gdevpdfs.c => gdevpstr.c,
    gdevpdft.c, gdevpsdf.c)

    Adds a PostScript writer (pswrite), similar to the PDF and PCL XL drivers.
    Currently this handles fill/stroke graphics and Level 1 images; everything
    else (including text) is turned into bitmaps.  (devs.mak, gdevps.c)

    Changes the names of the PCL XL drivers from hpxmono/color to pxlmono/color.
    (devs.mak, gdevpx.c)

    Updates the "vector" device support interface.  THIS IS STILL SUBJECT TO
    CHANGE WITHOUT NOTICE.  (gdevvec.h, gdevpx.c, gdevvec.c)

    Makes the vgalib driver a page device.  This seems bizarre, but it's
    necessary for setpagedevice to work with it.  (gdevvglb.c)

    Updates some drivers for the new color mapping interfaces.  (gdevpx.c)

    Updates the user-contributed Canon LBP-8II and LIPS III driver.
    (gdevlbp8.c)

### Platforms

    Fixes bugs:
    	- The workaround for Ultrix's incorrect implementation of sh -e
    still didn't work.  (unixtail.mak)
    	- The definition of offset_of didn't work on the Mac.  (stdpre.h)

    Updates the OS/2 EMX linker command per input from a user.  (os2.mak)

### Fonts

    Adds .pss (apparently used by Adobe for Multiple Master font instances) to
    the list of extensions skipped by the GS_FONTPATH directory scanner.
    (gs_fonts.ps)

### Interpreter

    Fixes bugs:
    	- Programs that rebind null, true, and/or false could cause all
    kinds of problems.  We've only fixed a couple of the places that might be
    affected (findfont, quit), by wrapping an explicit "systemdict begin/end"
    around the code; fixing this completely would probably require wrapping this
    implicitly around almost every pseudo-operator, which would be too
    expensive.  (gs_fonts.ps, gs_lev2.ps)
    	- In a Level 2 system, grestoreall stopped one level too early.
    (zdevice2.c)
    	- setpagedevice didn't restore the stack properly if it got an
    error.  (gs_setpd.ps)

    Changes the GC pointer enumeration interface to reduce the number of
    'discarding const' warnings.  See under Library below.  (igc.c)

    Updates the interpreter for the change in the imager / graphics state split.
    (zpcolor.c)

    Makes the stack-restoring behavior of pseudo-operators non-optional.
    (interp.c)

### Interpreter (PDF)

    Fixes bugs:
    	- PDFDocEncoding and WinAnsiEncoding incorrectly had `minus' at
    position 45 rather than `hyphen'.  (gs_pdf_e.ps, gs_wan_e.ps)

### Streams

    Fixes bugs:
    	- A header file wasn't protected against double inclusion.
    (stream.h)
    	- any_abs was redefined.  (spngp.c)
    	- The CCITTFaxDecode filter didn't fully initialize the "previous
    line" for 2-D decoding, so if the very first line of data was 2-D, an
    out-of-bounds memory access could occur.  (scfd.c)

### Library

    Fixes bugs:
    	- gs_image_next could read too much data, causing errors at the
    interpreter level.  (gsimage.c)
    	- The bitmaps stored in the Pattern cache were usually freed,
    leaving dangling pointers.  (gsdcolor.h, gxpcache.h, gxpcolor.h, gsstate.c,
    gxpcmap.c)
    	- There was still one assignment to a const structure, and there
    were some unnecessary const-discarding casts.  (gxclread.c)
    	- If a character in a Type 3 font was defined by executing 'show'
    type commands, charpath did the wrong thing (didn't pick up the paths
    created by the inner show).  Similarly, if it uses 'stroke', true charpath
    did the wrong thing (appended the path rather than the strokepath path).
    (gxchar.h, gschar.c, gspaint.c)
    	- A header file wasn't protected against double inclusion.
    (gserror.h)
    	- The new fast implementation of rectfill didn't handle rectangles
    with negative width/height.  (bug introduced in 4.32) (gsdps1.c)
    	- Reading banded high-level images calculated the image height
    incorrectly, (usually) causing a rangecheck.  (gxclread.c)
    	- When reading band data, a memory fault could occur if the halftone
    cache hadn't been allocated yet.  (gxht.c)
    	- The imager state data for high-level images wasn't written soon
    enough.  (gxclimag.c)
    	- High-level images computed bounding boxes incorrectly, so they
    could write some garbage data in the band list, and could also fail to write
    some information.  (gsmatrix.h, gxmatrix.h, gxclimag.c)
    	- High-level images wrote the raster value incorrectly in the band
    list.  (gxclimag.c)
    	- Images with non-zero initial source X and non-portrait orientation
    were displaced on the page.  (In practice, this only applied to some banded
    high-level images.)  (gximage.c)
    	- The bounding box device didn't forward output_page calls, causing
    pages to be dropped or overprinted.  (gdevbbox.c)
    	- The band renderer considered all non-zero return codes as errors,
    rather than only negative codes.  (gxclread.c)
    	- An unnecessary extern hadn't been removed.  (gxclimag.c)
    	- Some macros didn't parenthesize uses of their arguments, causing
    syntax errors.  (gsrefct.h)
    	- The screen phase and color_info weren't set correctly when
    rendering bands.  (gsstate.h, gsht.c, gxclread.c)
    	- A header file didn't declare all the opaque types it used.
    (gsdevice.h)
    	- Indexed color spaces didn't work with banded images.  (They still
    don't -- the check for writing the color space, and the code for reading the
    table or map, are incomplete.)  (gxclist.h, gxclpath.h, gxclimag.c,
    gxclpath.c, gxclread.c)

    In preparation for implementing post-banding halftoning:

    	- Moves color rendering information, including alpha value, from
    graphics state to imager state; also moves the allocator pointer.  This is
    quite a subtle change, and may have a significant bug tail.  (gxdcolor.h,
    gxht.h, gxistate.h, gzstate.h, gschar.c, gsdps1.c, gspaint.c, gsstate.c,
    gxclread.c)

    	- Changes all the relevant color space and color mapping procedures
    so they take a const gs_imager_state * (and, in some cases, a [const]
    gx_device *) instead of a const gs_state *.  This is a
    non-backward-compatible change, but it only affects internal interfaces.
    (gsdcolor.h, gxcmap.h, gxcspace.h, gxdcconv.h, gxdcolor.h, gxdither.h,
    gxpcolor.h, gzht.h, gschar.c, gscie.c, gscolor.c, gscolor1.c, gscolor2.c,
    gscsepr.c, gsdevice.c, gsimage.c, gspcolor.c, gxcht.c, gxcmap.c, gxdcconv.c,
    gxdcolor.c, gxht.c, gximage.c, gximage[2345].c, gxpcmap.c)

    	- Changes the color and color space reference count adjustment
    procedures similarly, to take a gs_memory_t * instead of a gs_state_t *.
    (gxcspace.h, gscie.c, gscolor.c, gscolor2.c, gscsepr.c, gspcolor.c)

    	- Changes the gs_halftone in the graphics state from being part of
    the gs_state_contents to being an independent reference-counted object.
    This too may have a significant bug tail.  (gxht.h, gxistate.h, gsht.c,
    gsstate.c)

    	- Changes the image processing code so it no longer assumes that the
    gs_imager_state is actually a gs_state.  (gximage.h, gximage.c, gximage2.c,
    gximage3.c, gximage4.c, gximage5.c)

    	- Adds a unique ID value to device halftones, so that it's possible
    to detect (non-)changes quickly.  (gxdht.h, gsht.c)

    Finishes the code for writing and reading color rendering information in the
    band list.  This involves changes to several band list opcodes.  (gsht.h,
    gsht1.h, gxcldev.h, gxclist.h, gxclpath.h, gxdht.h, gzht.h, gsht.c, gsht1.c,
    gxclbits.c, gxclimag.c, gxclist.c, gxclread.c)

    Changes the garbage collector pointer enumeration procedure interface
    slightly to reduce the number of 'discarding const' warnings.  THIS IS A
    NON-BACKWARD-COMPATIBLE CHANGE for anyone who didn't use the
    ENUM_PTRS_BEGIN[_PROC] macro to start a pointer enumeration procedure (which
    should be no one).  (gsstruct.h, gsmemory.c)

    Corrects a few more needlessly const-discarding casts.  (gxfcache.h,
    gxccache.c)

    Checks for file reading errors when rasterizing bands.  (gxclread.c)

## Version 4.51 (limited) (2/9/97)

This version contains a more reasonable high-level PCL XL driver. The VMS build script is working again, we think.

### Procedures

    Fixes bugs:
    	- The gsdll_h macro wasn't defined all the places it was needed.
    (devs.mak, os2.mak)

### Drivers

    Continues to develop the "vector" driver infrastructure and the PCL XL
    driver.  EVERYTHING IN THESE FILES IS SUBJECT TO CHANGE WITHOUT NOTICE.
    (gdevvec.h, gdevvec.c)

    Brings the PCL XL driver up to usable quality for graphics.  Most
    fill/stroke graphics, and portrait-orientation bitmap images up to 8 bits
    per pixel, are converted directly to their PCL XL equivalents.  Text is
    still treated as bitmaps.  Both gray-scale and color output are now
    supported.  (devs.mak, gdevpx.c)

### Platforms

    Fixes bugs:
    	- When using gsos2.exe with gsdll2.dll, reducing the size of the
    page bitmap caused a limitcheck error with the message
        Failed to decommit memory in pm_alloc_bitmap, rc = 87  (gdevpm.c)
    	- The scripts that construct gconfig_.h failed on Ultrix, because
    Ultrix's implementation of sh -e is incorrect.  (unixtail.mak, ugcclib.mak)
    	- Some systems that have sys/times.h don't define CLK_TCK, making a
    compilation fail.  (time_.h)

### Interpreter

    Fixes bugs:
    	- An omitted semicolon wasn't detected by gcc.  (idict.c)

    Removes a source of unnecessary duplication by getting the revision number
    and date from version.mak.  (gs.mak, int.mak, version.mak, gscdef.c)

### Streams

    Fixes bugs:
    	- The minimum buffer sizes for the RunLengthDecode filter hadn't
    been changed to reflect the algorithm improvement made in release 4.38.
    (srld.c)

    Changes the RunLengthEncode filter so it can make progress with only a
    2-byte output buffer.  (srlx.h, srle.c)

### Library

    Fixes bugs:
    	- Because of a typo, the slow general algorithm was always used for
    monochrome images.  (Performance bug only, but a serious one.)  (gximage2.c)
    	- Dots (zero-length lines with round caps and zero dot length)
    caused an infinite loop.  (bug introduced in 4.40)  (gxstroke.c)
    	- Some image data unpacking procedures were always required, but
    weren't always included.  (bug introduced in 4.50) (gximage.c, gximage0.c,
    gximage3.c)
    	- Images with 8 bits per pixel and non-identity Decode produced
    garbage.  (bug introduced later than 4.03) (gximage0.c)
    	- Some necessary casts and omitted punctuation weren't detected by
    gcc.  (gxpath.h, gsargs.c, gsstate.c, gxclread.c, gxpdash.c)
    	- The band list became confused if a band had no commands at all.
    (gxclread.c)
    	- If a path included a closepath followed by a moveto to the same
    point, it could be written incorrectly in the band list.  (bug probably
    introduced in 3.60) (gxclpath.c)

    Changes some internal computations for arcs from float to double for greater
    accuracy.  (gspath1.c)

## Version 4.50 (limited) (1/31/97)

This release contains an experimental high-level PCL XL driver, a little more support for CID/CMap fonts, and the usual bug fixes. NOTE: the VMS build script is known to be out of sync with the makefiles again; we still don't see any alternative to constant struggles with this problem.

### Documentation

    Corrects the -h message, which gave an incorrect file name for the bug
    report form.  (imainarg.c)

    Removes documentation for 16-bit MS-DOS platforms with the Borland compiler.
    (fonts.txt, make.txt, new-user.txt, use.txt)

### Procedures

    Fixes bugs:
    	- The Watcom library makefile didn't define the directory
    information for libpng and zlib.  (watclib.mak)

    Moves the selection of band list implementation (file- vs. RAM-based) and
    the compression filter for RAM-based band lists up to the top-level
    makefiles.  Again, this is a NON-BACKWARD-COMPATIBLE procedure change.
    (lib.mak, *.mak)

    Moves the selection of version number for all platforms (except VMS, as
    usual) to a separate file.  This will reduce the number of files that need
    editing when the version number changes.  (ansihead.mak, cc-head.mak,
    gcc-head.mak, ugcclib.mak, version.mak, tar_cat)

### Drivers

    Fixes bugs:
    	- An error in the (unsupported) SGI RGB driver could cause crashes
    or incorrect output.  (gdevsgi.c)

    Starts to create a framework for structured output ("vector") drivers (PDF,
    PostScript, PCL XL, etc.)  (gdevbbox.h, gdevvec.h, gsdcolor.h, gsstruct.h,
    gxdevice.h, gdevvec.c)

    Moves default page size parameters to a more accessible header.  (gdevprn.h,
    gxdevice.h, gdevx.c)

    Adds a driver that produces properly structured PCL XL output.  This is
    highly experimental and not ready for use yet.  (gdevpx.c)

### Platforms

    Removes support for 16-bit MS-DOS platforms with the Borland compiler.  For
    the moment, 16-bit MS Windows is still supported.  (bc.mak, bcflags.mak,
    bclib.mak, tc.mak)

### Interpreter

    Fixes bugs:
    	- File-based CIDFonts (with delayed, incremental loading of
    character outlines) didn't work.  (gs_cidfn.ps)

    Finishes implementing the definition of CMap resources, except for
    rearranged fonts.  (gs_cidfn.ps, gs_cmap.ps)

    Adds a little more CMap support code.  (zcid.c)

    Removes the .setcurrentfile operator, since it doesn't solve the problem it
    was intended to address.  (zcontrol.c)

    Adapts the interpreter to use the new argument processing code.
    (imainarg.c)

### Streams

    Fixes bugs:
    	- The CCITTFaxDecode filter could access as much as 3 bytes beyond
    the end of a buffer, causing an invalid memory access.  (This is essentially
    the same bug that was fixed for the CCITTFaxEncode filter in 4.38.)
    (scfd.c)

### Library

    Fixes bugs:
    	- Painting an image without having set up any halftone could cause a
    crash.  (gxht.c)
    	- In a very obscure case, an occasional scan line of landscape
    images could get corrupted.  (gximage0.c)
    	- Because of a rounding error, patterns could fail to be painted in
    certain cases.  (gxpcolor.h, gspcolor.c, gxpcmap.c)
    	- Very large line widths or miter limits could cause the computation
    of stroke expansion to overflow.  (gxpaint.h, gdevbbox.c, gxclpath.c,
    gxstroke.c)
    	- The phase could be incorrect for simple patterns.  (gspcolor.c)
    	- The default implementation of copy_mono used an incorrect
    RasterOp.  (gdevdflt.c)
    	- The default implementation of fill_masked didn't increment the row
    pointer, causing characters to appear as solid rectangular blocks.
    (gxdcolor.c)

    Eliminates an unnecessary gsave and grestore from rectfill and rectstroke if
    the path was null.  (gsdps1.c)

    Adds a limit on the amount of space that the default (C heap) allocator will
    allocate, and a record of the maximum amount allocated, to help testing
    embedded products.  (gsmemory.c)

    Changes the band list algorithm for deciding how many replicas of a halftone
    tile to store in the tile cache.  The previous algorithm was too liberal,
    which could cause the cache to overflow and many unnecessary bitmaps to be
    written in the band list.  (gxclbits.c)

    Writes clipping with a rectangle more compactly in the band list.
    (gxfixed.h, gxclpath.c)

    Adds new band list commands for representing 90- and 180-degree arcs
    compactly.  (gxclpath.h, gxclpath.c, gxclread.c)

    Repackages handling of general monochrome images, color images, and 12-bit
    and interpolated images, so that they are included optionally rather than in
    all configurations.  (int.mak, lib.mak, gximage.h, gximage.c,
    gximage[12345].c)

    Changes the structure definition for devices to include no-op pointer
    enumeration and relocation, so they can have subclasses.  (gxdevice.h)

    Adds a library facility for processing command line arguments with
    @-expansion.  (gsargs.h, gsargs.c)

## Version 4.41 (private) (1/21/97)

This release adds a PCL XL output driver, and a few performance improvements.

### Procedures

    Fixes bugs:
    	- The zlib library used an incorrect header file when compiling.
    (zlib.mak)

    Changes the names of the preprocessor symbols indicating the presence of
    system header files to be consistent with the ones used by GNU configure.
    (dvx-tail.mak, ugcclib.mak, unixtail.mak, vms.mak; dirent_.h, time_.h;
    gp_unix.c)

    Changes the method for choosing the compression filter for RAM-based band
    lists.  This is a NON-BACKWARD-COMPATIBLE change in the makefile.  (lib.mak)

### Drivers

    Adds black-and-white and 8-bit gray PCL XL (PCL 6) drivers for the LaserJet
    5 and 6 family.  This driver is extremely simple and just emits bitmaps;
    future drivers will use more PCL XL high-level constructs.  (gdevlj56.c)

### Fonts

    Updates the free font distribution to add the URW Grotesk and Antiqua fonts.

### Interpreter

    Fixes bugs:
    	- gs -h and -v returned with a non-zero exit code on all platforms.
    (This is necessary under Windows, to keep the message visible on the screen,
    but nowhere else.)  (imainarg.c)
    	- Resizing a dictionary could exceed dict_max_size, causing memory
    corruption.  (dstack.h, idict.h, idict.c, zdict.c)

    Adds .setlinecap and .setlinejoin that can use the extended range of line
    cap/join values, and redefines setlinecap and setlinejoin in terms of them.
    (gs_init.ps, zgstate.c)

### Streams

    Fixes bugs:
    	- The CCITTFaxDecode filter with EncodedByteAlign = true skipped to
    a byte boundary before checking for an EOL.  This may be wrong if EndOfLine
    = true; we aren't at all sure what should happen if EndOfLine = false.
    (scfd.c)

    Adds a "no wrapper" option to the zlib streams, to optionally suppress the
    time-consuming integrity checksum computation.  (szlibx.h, szlibc.c,
    szlibd.c, szlibe.c)

### Library

    Fixes bugs:
    	- Dashed lines with zero-length drawn segments (dots) that fell
    exactly on a corner produced inappropriate output.  (pcl/test19.pxs)
    (gxpdash.c, gxstroke.c)
    	- Dashed lines didn't set the segment notes properly.  (gxpdash.c)
    	- The bounding box device didn't free a bookkeeping structure at the
    end of processing an image.  (gdevbbox.c)
    	- Curve points could get computed incorrectly when using emulated
    floating point.  (gxpcopy.c)
    	- The 1-element cache for curve_x_at_y didn't work if Y was
    decreasing.  (gxfixed.h, gxpcopy.c)

    Distinguishes between error and informational exits.  (stdpre.h)

    Defines and checks maximum values for line cap and join parameters.
    (gslparam.h, gsline.c)

    Removes the 'not last' segment note, since it is not used for anything.
    (gxpath.h, gspath1.c, gxpath2.c, gxpcopy.c, gxpflat.c, gxstroke.c)

    Changes the memory freeing algorithm for RAM-based band lists back to the
    original one, since the "improved" one had more bugs than it was worth
    chasing.  (gxclmem.c)

    Speeds up the A * B / C algorithm a little.  (gsmisc.c)

    Speeds up curve_x_at_y by recognizing more cases that don't require the slow
    A * B / C algorithm.  (gxpcopy.c)

    Changes the path filling code so it uses fill-by-trapezoids even if
    fill_adjust is zero, as long as the flatness is at least 1 pixel.
    (gxfill.c)

    Removes the (unneeded) floating point operations from gx_curve_log2_samples.
    (gxpflat.c)

    Changes the memory-based implementation of band lists so that it constructs
    the compressor and decompressor by calling procedures rather than
    instantiating templates: this allows setting filter parameters to
    non-default values.  (gxclmem.h, gxcllzw.c, gxclmem.c, gxclzlib.c)

## Version 4.40 (private) (1/13/97)

This version finally handles the last graphics model discrepancies between PostScript and PCL, by correctly implementing null joins, minimum dot lengths, and tangent-aligned curve ends. It also contains some significant performance improvements, and as usual a few bug fixes.

### Documentation

    Documents the new accurate curves and path dashing operators.
    (language.txt)

### Utilities

    Adds switches for genconf to set and unset a prefix for file names.
    (genconf.c)

### Drivers

    Adds recognition of the new Distiller 3.0 parameters to the PDF writer.
    (None of them have any effect yet.)  (gs_pdfwr.ps, gdevpdfx.h, gdevpdf.c,
    gdevpdfp.c)

    Converts all the output functions in the PDF writer from being file-based to
    using streams, in anticipation of adding compression.  (gdevpdfs.h,
    gdevpdfx.h, gdevpdf*.c, gdevpdfs.c)

### Interpreter

    Adds operators for accessing the new accurate curves flag in the graphics
    state.  (zgstate.c)

    Adds an operator for invoking gs_dashpath.  (zpath1.c)

### Interpreter (PDF)

    Fixes bugs:
    	- Indexed color spaces whose base space was a CIE space caused an
    error.  (pdf_draw.ps)

### Library

    Fixes bugs:
    	- A pointer was declared const incorrectly.  (gxcpath.c)
    	- Filling with a pattern often failed to pass a non-null bitmap ID,
    causing excessive writing in the band list.  (Performance bug only.)
    (gspcolor.c)
    	- The bounding box device didn't discount copy_mono or draw_line
    operations drawing in white.  (gdevbbox.c)
    	- The bounding box device didn't read out the bounding box correctly
    as the PageBoundingBox device parameter.  (It did return it correctly
    through the gx_device_bbox_bbox procedure.)  (gdevbbox.c)
    	- The default implementation of fill_triangle drew nothing or
    incorrect output if the corners of the triangle were specified in certain
    orders (ax < 0 or bx < 0) (i.e., the previous "fix" had a bug).
    (gdevddrw.c)

    Changes tile size from always being set in all bands to being 'known' by
    bands individually.  (gxclist.h, gxcldev.h, gxclbits.c, gxclist.c)

    Computes an additional value in advance when rendering images.  (gximage.h,
    gximage1.c, gximage2.c)

    Replaces some slow loops with calls of memmove.  (gxclmem.c)

    Provides a fixed-point implementation of A * B / C for machines with slow
    floating point.  (gxfixed.h, gsmisc.c)

    Extends the "device color" type to implement filling masked regions as well
    as rectangles.  (gxdcolor.h, gdevdflt.c, gspcolor.c, gxcht.c, gxdcolor.c,
    gxht.c)

    Makes unclipped monobit portrait and landscape images and image masks use
    the new masked fill capability of device colors.  (gximage.h, gximage.c,
    gximage1.c, gximage2.c)

    Adds a macro for determining pointer alignment.  (stdpre.h, gdevdflt.c)

    When floating point is slow, uses a different, faster algorithm for
    gx_curve_x_at_y.  (gxpcopy.c)

    Improves performance by adding a one-element cache for gx_curve_x_at_y.
    (gzpath.h, gxpcopy.c)

    Reduces overhead when banded images are pre-rasterized (currently, always).
    (gxclimag.c)

    Adds a rendering cost estimate field to each band in a band list.  This
    field isn't actually used for anything yet; eventually, the intent is that
    bands with a high cost will get rendered, and stored in compressed form,
    before starting the engine.  (gxclist.h)

    Adds the concept of 'notes' for path segments, to allow remember what
    segments constitute a single curve or arc.  Currently we set these properly
    for everything except dashed paths.  (gxclpath.h, gxpath.h, gzpath.h,
    gspath1.c, gxclpath.c, gxclread.c, gxpath.c, gxpath2.c, gxpcopy.c)

    When the dot length is non-zero, changes curve stroking to always use bevel
    joins within each curve rather than the current join.  This prevents a
    "bristly" look with no join and butt caps.  (gxstroke.c)

    Adds an "accurate curves" capability that makes the last line segment of a
    flattened curve actually be tangent to the curve, which in turn makes
    flat-end caps be correctly perpendicular to the tangent.  (gxpath.h,
    gxpcopy.c)

    Adds an "accurate curves" flag in the graphics state.  (gsline.h,
    gxclpath.h, gxistate.h, gsline.c, gspath.c, gspath1.c, gxclpath.c,
    gxclread.c, gxfill.c, gxstroke.c)

    Changes the meaning of "no join" (gs_join_none) so that instead of producing
    no join and butt caps, it produces whatever the current cap is.  This is
    compatible with the H-P definition.  (gxstroke.c)

    Implements non-zero dot length for dash patterns.  (gxpdash.c)

    Splits off the curve flattening algorithms into a separate file.
    (gxpcopy.c, gxpflat.c)

## Version 4.39 (limited) (1/1/97)

This version was created only to accompany a release of the PCL XL interpreter. It was withdrawn the day after it was released, because the tools used to produce it put the wrong files in the filesets.

### Documentation

    Adds a more detailed description of the third-party ps_view viewer
    interface.  (new-user.txt)

    Corrects an error in a reference to the PSLRM.  (lib.txt)

    Documents the change in .makeoperator.  (language.txt)

    Updates the FTP location of the zlib sources.  (zlib.mak)

### Procedures

    Fixes bugs:
    	- The Unix library makefile didn't include the necessary definitions
    for libpng and zlib.  (ugcclib.mak)

    Allows selecting the compression filters for memory-based band lists in the
    makefile.  Makes zlib (deflate) the default compressor for memory-based band
    lists.  (lib.mak)

### Utilities

    Fixes bugs:
    	- prfont.ps wouldn't print unencoded characters in Type 42 fonts.
    (prfont.ps)

### Drivers

    Fixes bugs:
    	- The H-P monochrome driver didn't put out enough initialization
    commands at the beginning of each page to make each page printable
    independently.  (gdevdjet.c)

### Interpreter

    Changes ref_stack_count_inline so it never does a procedure call.
    (istack.h)

    Changes .makeoperator so that operator procedures save the stack depths, and
    restore the stack pointers (if possible) if the operator encounters an
    error.  This is a NON-BACKWARD-COMPATIBLE CHANGE; it requires rewriting the
    'stop' and 'stopped' pseudo-operators (and, if there were any, any other
    pseudo-operators that interact with the error handling machinery) in C.
    (gs_init.ps, interp.c, zcontrol.c)

    Adds recognition of the LeadingEdge, MediaClass, and RollFedMedia keys in a
    page device dictionary, per the Adobe supplement for their version 2017
    interpreter.  This involves a NON-BACKWARD-COMPATIBLE change to the
    (undocumented) .matchpagesize operator.  (gs_setpd.ps, zmedia2.c)

    Makes necessary changes for compatibility with the added parameters for the
    zlib filters.  (zfzlib.c)

### Streams

    Fixes bugs:
    	- The zlib encoder returned EOFC when it should have returned 0.
    (szlibe.c)

    Adds optional parameters and reset procedures for the zlib filters.
    (szlibx.h, szlibc.c, szlibd.c, szlibe.c)

### Library

    Fixes bugs:
    	- Displaying characters with a non-standard RasterOp could cause an
    invalid memory access.  (gdevdflt.c)
    	- Banding sometimes used an incorrect RasterOp.  (gxclread.c)
    	- When banding, mixing Patterns and halftones could confuse the
    bookkeeping of tile size, leading to incorrect generation of the band list
    and error messages or confusion when rasterizing.  (gxclist.h, gxclbits.c,
    gxclread.c)
    	- If only the dash pattern offset changed, and not any of the other
    dash-related parameters, the new offset wasn't written in the band list,
    causing incorrect output.  (gxclpath.c)
    	- Oversized halftone tiles didn't report their error code properly.
    (gxclbits.c)
    	- Oversized halftone tiles with RasterOp caused an error.
    (gxclist.c)
    	- When banding, RasterOp transfers that crossed a band boundary
    didn't access the correct source data on bands other than the first.
    (gxclist.c)
    	- There were redundant copies of the code for writing a RasterOp
    value in the band list.  (gxclimag.c, gxclpath.c)
    	- Oversized patterns or halftones produced garbled output.
    (gxclbits.c)
    	- The check for oversized patterns or halftones was slightly
    incorrect, leading to the possibility of writing out a tile that would
    overflow the reading buffer and corrupt memory.  (gxclbits.c)
    	- When banding, RasterOp wasn't applied to fill and stroke
    operations, and wasn't applied correctly to characters.  (gdevdflt.c,
    gxclimag.c, gxclread.c)
    	- The RasterOp-related optimizations for black-and-white images
    sometimes produced incorrect output.  (gximage.c, gximage2.c)
    	- The default implementation of fill_triangle didn't draw anything
    if the corners of the triangle were specified in certain orders (ax < 0 or
    bx < 0).  (gdevddrw.c)
    	- Painting with a Pattern could pass out-of-range phase values to
    driver procedures.  (gspcolor.c)
    	- Because of an off-by-1 error, halftones or patterns passed through
    the band list could write past the end of their allocated space in the band
    tile cache, leading to incorrect output or possible arithmetic exceptions or
    memory access errors.  (gsbitops.c)

    Adds -Z: for printing only the minimal command list statistics.  (gxclist.c,
    gxclread.c)

    Expands band list tracing so it includes all of the data associated with the
    command, not just the command name and a few command parameters.
    (gxclread.c)

    Adds free lists for strings.  Currently these are only used in
    non-garbage-collected environments.  (gxalloc.h, gsalloc.c, gsnogc.c)

    Adds a procedure for copying a path structure, and an (internal) accessor
    for the current path in the graphics state.  (gxpath.h, gspath.c, gxpath.c)

    Speeds up filling characters with halftones a little bit.  (gdevdflt.c)

    Changes the memory-based implementation of band lists so it can use any
    compression / decompression filter, so it only compresses when it has
    allocated a specified amount of buffer storage, and so it releases its
    buffer storage at the end of each page.  (gxclmem.h, gxclmem.c)

    Speeds up counting the number of 1-bits in a byte, which is used in some
    image processing algorithms.  (gsbittab.h, gsbittab.c)

    Reduces the band list space required for changing tile size.  (gxcldev.h,
    gxclbits.c, gxclread.c)

## Version 4.38 (limited) (12/20/96)

Adds support for a couple of undocumented features in Type 1 fonts.

### Interpreter

    Adds handling of the Type 1 font subroutineNumberBias (an optional entry in
    the Private dictionary) and lenIV = -1 features at the interpreter level.
    (zchar1.c, zfont1.c)

### Streams

    Fixes bugs:
    	- The CCITTFaxEncode filter could access as much as 3 bytes beyond
    the end of a buffer, causing an invalid memory access.  (scfe.c)

    Changes the RunLengthDecode filter so it can make progress (produce output)
    with only a 1-byte output buffer.  (srlx.h, srld.c)

### Library

    Fixes bugs:
    	- The sine and cosine of multiples of 90 degrees weren't exact.
    (gxfarith.h, gsmisc.c)
    	- The expanded bounding box computation for strokes didn't take into
    account the possibility of overflow.  (gxstroke.c)
    	- The allocator didn't fill freed strings with the 'free' mark.
    (gsalloc.c)
    	- When using a pattern with RasterOp, the phase was computed
    incorrectly, leading to anomalous filling patterns.  (gspcolor.c)
    	- Patterns with a non-zero translation in the matrix passed to
    makepattern didn't translate the pattern origin properly.  (gxcolor2.h,
    gxpcolor.h, gspcolor.c)

    Adds a subroutineNumberBias field to Type 1 fonts.  This is an undocumented
    feature of the Type 1 font format.  (gxfont1.h, gstype1.c)

    Interprets lenIV = -1 in Type 1 fonts as meaning that the CharStrings are
    unencrypted.  This too is an undocumented feature of the Type 1 format.
    (gxfont1.h, gxtype1.h, gstype1.c, gstype2.c)

    Changes gs_clippath so it returns more reasonable outlines.  (There are too
    many programs that rely on being able to stroke the result of clippath, even
    though both the Adobe and H-P literature specifically say the results are
    unpredictable.)  (gxcpath.h, gxcpath.c)

## Version 4.37 (limited) (12/10/96)

This version implements separate halftone phase for source and texture, required for PCL XL implementation.

### Fonts

    Fixes bugs:
    	- Loading a native TrueType font without a 'post' table caused an
    error.  (gs_ttf.ps)

### Interpreter

    Extends the interpreter to handle the new separate halftone phases for the
    RasterOp source and texture.  (gs_dps1.ps, zdps1.c)

    Makes a small change to accommodate a library change supporting Type 2
    charstrings.  (zfont1.c)

### Interpreter (PDF)

    Implements the FontFile2 key for embedded TrueType fonts.  (pdf_font.ps)

    Starts to implement the FontFile3 key for compressed Type 1 fonts.  This
    code is currently disabled, because none of the necessary underlying C is
    written yet.  (pdf_font.ps)

### Library

    Fixes bugs:
    	- The floating point emulator often returned incorrect results (too
    many bugs to list).  (This is not used in any standard configuration.)
    (gsfemu.c)
    	- The new copy_for procedure for gstates incorrectly declared an
    argument as const.  (gxstate.h, gsstate.c)
    	- If a curve had to be split twice along the same axis to make it
    monotonic, the split points could still be returned in the wrong order,
    possibly causing curved edges to turn into straight lines, and the algorithm
    still produced the wrong results if the curve had to be split twice along a
    single axis.  This is the second time we have "fixed" these problems and the
    4th time we have "fixed" the curve monotonizing algorithm.  (gxpcopy.c)
    	- Setting halftones cause a memory leak, because the subsidiary
    objects of the device halftone weren't freed properly.  Fixing this required
    changing the graphics state implementation from allocating a device halftone
    for each gstate to managing the device halftone with reference counting.
    (gxdht.h, gzstate.h, gsht.c, gsstate.c)

    Provides an optimized version of ldexp for FPU-less configurations, and
    changes one key algorithm to use it.  (gxfixed.h, gsmisc.c, gxpcopy.c)

    Speeds up imagemask with a halftone a little.  (This will eventually require
    more serious optimization.)  (gximage2.c)

    Adds a -Z* switch for tracing varieties of image rendering.  (gximage.c)

    Recognizes that if the logical operation is equivalent to D = S (after
    accounting for a constant texture, if any), or if it is equivalent to D = ~S
    or D = D {&,|}{S,~S} and D and S are both monobit and both colors are pure,
    imaging with RasterOp can be executed without invoking RasterOp.  (gsropt.h,
    gximage.c)

    Makes coordinate transformations with landscape matrices execute as fast as
    with portrait matrices.  (gxmatrix.h, gscoord.c, gsmatrix.c)

    Adds some sketch code for interpreting Type 2 charstrings.  It compiles, but
    it makes no pretense of being runnable.  (gstype1.h, gxop1.h, gxtype1.h,
    gstype2.h, gxfont1.h, gstype1.c, gstype2.c)

    Extends the library to allow setting separate halftone phases for the
    RasterOp source and texture, which is needed to implement halftone screens
    that behave like those in H-P's PCL XL printers.  (gscsel.h, gsstate.h,
    gxcmap.h, gxcspace.h, gxdcolor.h, gxdither.h, gxpcolor.h, gzht.h, gzstate.h,
    gscie.c, gscsepr.c, gsht.c, gspcolor.c, gxcht.c, gxcmap.c, gxdcolor.c,
    gxht.c, gximage.c, gximage[2345].c, gspcmap.c) ****** STILL NEED TO UPDATE
    BANDING CODE, grep FOR phase ******

    Removes the rc_header member from the gs_halftone structure, since we don't
    need it after all.  (gxht.h)

## Version 4.36 (limited) (12/3/96)

This version fixes a number of library bugs related to RasterOp, Patterns, and memory management.

### Documentation

    Changes the definition of texture transparency to match the peculiar H-P
    specification.  (drivers.txt, language.txt)

### Drivers

    Fixes bugs:
    	- x_get_bits didn't flush updates to the frame buffer, leading to
    possibly incorrect data being returned.  (gdevx.c)
    	- x_get_bits added padding to the scan line being copied, possibly
    corrupting memory.  (gdevx.c)

    Changes the x11mono driver to define white = 0, black = 1 to more closely
    model black-and-white printers.  (This is an internal change that doesn't
    affect the output.)  (gdevxalt.c)

### Interpreter

    Removes some code that is no longer needed, by virtue of the fix for the
    memory leak in Pattern remapping.  (zpcolor.c)

### Library

    Fixes bugs:
    	- Patterns wider than 1024 bits caused a rangecheck.  (gxclip2.h,
    gxclip2.c)
    	- Dash patterns never got freed.  The fix for this slows down gsave
    and grestore slightly, but we don't see any way around it.  (gsline.c,
    gsstate.c)
    	- If the CTM was very non-uniform in X and Y, stroke sometimes
    didn't recognize thin lines as being thin, leading to dropouts.
    (gxstroke.c)
    	- RasterOps that didn't use S or T still took S or T transparency
    into account.  (gdevmrop.c)
    	- RasterOps with no source didn't handle the possibility that the
    device color for black might have a value other than 0.  (gxdcolor.h,
    gspcolor.c, gxcht.c, gxdcolor.c, gxht.c)
    	- White pixels in halftones on black-and-white devices apparently
    are *not* supposed to be treated as opaque for RasterOp.  (gxcht.c, gxht.c)
    	- clippath caused memory to be lost until a restore or a garbage
    collection.  (gspath.c)
    	- Clipping lists weren't ever freed, and clipping paths sometimes
    weren't freed, causing memory to be lost until a restore or a garbage
    collection.  (gzacpath.h, gxacpath.c, gxcpath.c)
    	- Freeing a pattern instance referenced a pointer after it had been
    freed, causing an invalid memory access.  (gspcolor.c)
    	- Remapping a Pattern color lost track of the temporary gstate,
    memory devices, and possibly the mask, causing memory to be lost until a
    restore or GC.  (gxpcolor.h, gxpcmap.c)
    	- Remapping a Pattern color could cause paths to be marked as
    shared, preventing them from being freed until a restore or GC.  (gxpcmap.c)

    Enhances the non-tracing garbage collector so that if there are no strings
    allocated at all, it resets the string allocation pointers.  (gsnogc.c)

    Optimizes the black-and-white RasterOp implementation by recognizing cases
    that can be implemented directly by fill_rectangle, copy_mono, or
    tile_rectangle.  (gdevmrop.h, gsropt.h, gdevmrop.c, gsroptab.c)

    Changes -ZA so it no longer produces [P] tracing messages for path
    construction.  (gxpath.c)

    Adds a gx_pattern_cache_winnow procedure for selectively removing entries
    from the Pattern cache, similar to gx_purge_selected_cached_chars.
    (gscolor2.h, gxpcolor.h, gxpcmap.c)

    Adds the Pattern UID to Pattern cache entries.  (gxpcolor.h, gxpcmap.c)
    ****** MUST HANDLE XUID POINTERS ON GC (RELOC) & RESTORE (CLEAR LIKE HT
    CACHE) ******

    Makes gs_gstate free the path representation of the clipping path if it's a
    rectangle, since reconstructing it is cheap and otherwise the path segments
    would not be freeable until a restore or GC.  (gsstate.c)

    Extends the "client data" interface for gstates so that the copy procedure
    can determine why it is being called.  (gxstate.h, gsstate.c)

## Version 4.35 (limited) (11/24/96)

This contains the usual bug fixes, and two minor enhancements: an option for handling EPSF files with binary headers, and support for file-based resources.

### Documentation

    Documents the new EPSF-reading capability.  (gs.mak)

### Procedures

    Fixes bugs:
    	- Some obsolete definitions were accidentally left in the rules for
    compiling fonts into the executable.  (int.mak)

### Interpreter

    Fixes bugs:
    	- initgraphics left the current color space in an inconsistent
    state.  (bug introduced in 4.32) (zgstate.c)
    	- restore didn't properly rebind FontDirectory to either Local or
    SharedFontDirectory according to the current VM selection.  (gs_dps1.ps)
    	- If FontDirectory was redefined, many things broke.  (gs_ccfnt.ps,
    gs_dps1.ps, gs_fonts.ps, gs_pdfwr.ps)
    	- If a resource provided a file name but the file couldn't be
    opened, an error occurred.  (gs_res.ps)
    	- flushfile didn't work with procedure-based streams.  (zfileio.c)

    Adds a feature (epsf.dev) that allows the interpreter to recognize and
    handle MS-DOS EPSF files with a binary header.  (int.mak, gs_epsf.ps,
    gs_init.ps, pdf_main.ps)

    Adds (internal) .getuserparam and .getsystemparam operators for getting the
    value of a single user or system parameter.  (gs_lev2.ps, zusparam.c)

    To support file-based resources, implements the FontResourceDir,
    GenericResourceDir, and GenericResourcePathSep system parameters, and
    ResourceFileName for the built-in resource categories.  (gs_init.ps,
    gs_lev2.ps, gs_res.ps)

### Streams

    Fixes bugs:
    	- The 2-D CCITTFaxDecode filter became confused if a buffer boundary
    fell between a horizontal make-up code and its terminating code, typically
    causing an ioerror.  (scfd.c)

### Library

    Fixes bugs:
    	- Using the null color could confuse the reference counts for color
    spaces, causing memory access errors.  (gscolor.c)
    	- Images with CombineWithColor = true caused memory access error,
    because a structure element wasn't initialized.  (gdevmrop.c)
    	- gs_setnullcolor tried to return an error code, even though it was
    declared as returning void.  (Why doesn't gcc catch this??)  (gscolor.h,
    gscolor.c)
    	- gs_setnullcolor was declared inconsistently as taking a const or
    non-const argument.  (gscolor.h)
    	- Small color tiles in the band list were not read in correctly.
    (gxclread.c)
    	- The band list could get confused, causing ioerrors, invalid memory
    accesses, or garbled output, because the algorithms for computing the size
    of bitmaps when writing and when reading had gotten inconsistent.  This code
    has been broken and "fixed" at least 4 or 5 times.  (gxcldev.h, gxclbits.c,
    gxclread.c)
    	- When using banding, characters that extended off the page
    vertically in the -Y direction came out garbled.  (gxclimag.c)
    	- The bounding box device didn't compute the box correctly for
    trapezoids.  (gdevbbox.c)
    	- The fastest case of rendering monochrome images could cause
    unaligned data accesses.  (bug introduced recently.)  (gximage.h,
    gximage1.c)
    	- TrueType characters with no contours could cause an invalid memory
    access.  (gstype42.c)
    	- Composite TrueType characters weren't rendered properly.
    (gstype42.c)

    Adds a get_outline procedure to the Type 42 font header, to provide a
    callback for getting the outline data for a glyph.  (gxfont42.h, gstype42.c)

## Version 4.34 (limited) (11/18/96)

This release adds a little more support for CID-keyed fonts and for PCL emulation, and a bit more of the machinery for passing images through the band list.

### Documentation

    Fixes bugs:
    	- The RasterOp source device wasn't listed as an internal device in
    drivers.txt.  (drivers.txt)

    Corrects a statement regarding the pstotext license.  (new-user.txt)

### Procedures

    Fixes bugs:
    	- The Watcom makefile for the library didn't work properly if
    certain variables were overridden from the command line.  (watclib.mak)
    	- The library code inadvertently depended on an interpreter header
    file.  (*.mak)

### Drivers

    Fixes bugs:
    	- Some very picky compilers complained about assigning 0 to a
    variable of an enum type.  (gdevpdfx.h, gdevpdf.c)

### Interpreter

    Fixes bugs:
    	- Some very picky compilers didn't like a cast from a pointer type
    to an int type.  (idebug.c)
    	- Some very picky (and non-ANSI-compliant) compilers didn't allow
    assigning an int to a variable of enumerated type.  (zfont2.c, zht2.c)
    	- The library code inadvertently depended on an interpreter header
    file.  (iref.h)

    Restructures the font building code slightly to support CID fonts better.
    (gs_cidfn.ps, bfont.h, zcid.c, zfont0.c, zfont1.c, zfont2.c, zfont42.c)

    Adds a .setcurrentfile operator to allow disk-based fonts to keep their file
    open.  (gs_cidfn.ps, zcontrol.c)

### Streams

    Fixes bugs:
    	- Some very picky compilers didn't like the computation (const byte
    *)0 - 1.  (stream.c)
    	- A cast to ulong was omitted.  (smtf.c)
    	- Some compilers got confused by typedefs in the zlib header files.
    (szlibd.c, szlibe.c)

### Library

    Fixes bugs:
    	- A header file didn't select the proper system header on all POSIX
    systems.  (malloc_.h)
    	- A subclass/superclass type discrepancy upset some compilers.
    (gsline.h, gsline.c, gxpdash.c)
    	- Some very picky compilers didn't accept the previous definition of
    the offset_of macro.  (stdpre.h)
    	- Some very picky (and non-ANSI-compliant) compilers didn't like
    mixing int and enumerated types.  (gsropt.h, gzstate.h, gdevmrop.c,
    gdevrrgb.c, gsrop.c, gxclist.c)
    	- A cast was missing.  (gslib.c)
    	- The gs_setxxxtransparent procedures interpreted their argument
    backwards (i.e., as "opaque" rather than "transparent").  (gsrop.c)
    	- Intersecting clipping paths didn't reset the logical operation to
    the default, causing a possible crash.  (gsrop.h, gsrop.c, gxacpath.c)
    	- Pattern accumulation didn't reset the logical operation to the
    default, possibly causing incorrect output.  (gspcolor.c)
    	- If a Type 1 character ended with a curve and a closepath, a
    microscopic line could result, causing output anomalies.  (gstype1.c)
    	- Stroking a path with a mix of thin and non-thin lines could cause
    extraneous lines to appear.  (gxstroke.c)
    	- Zero-width rectangles were painted even when fill adjustment was
    turned off.  (gxpaint.c, gxstroke.c)
    	- The algorithm for dividing a curve into monotonic pieces could
    produce incorrect results, causing anomalies when filling curved regions
    with zero fill adjustment.  (gxpcopy.c)
    	- The algorithms for outside clipping were wrong, causing some
    inside regions not to be clipped.  (gxcpath.c)
    	- The white pixels in halftones weren't treated as unconditionally
    opaque for RasterOp.  (gxht.c, gxcht.c)
    	- Images with RasterOp didn't work properly.  (gdevmrop.c,
    gximage[2345].c, gxpcmap.c)
    	- The library code inadvertently depended on an interpreter header
    file.  (gxalloc.h, genarch.c)
    	- An important optimization for stroking (recognizing portrait,
    landscape, and unscaled CTMs) was commented out.  WE DON'T HAVE ANY RECORD
    OF WHY WE DID THIS, AND RESTORING IT MAY INTRODUCE NEW BUGS.  (gxstroke.c)
    	- Bitmap images with non-zero data_x values were passed through the
    band list incorrectly, possibly causing vertical "streaks" in the output.
    (gxcldev.h, gxclread.c)
    	- If a curve had to be split twice along the same axis to make it
    monotonic, the split points were returned in the wrong order, possibly
    causing curved edges to turn into straight lines.  (gxpcopy.c)

    Changes the debugging printout format for paths so the output can be
    processed mechanically more easily.  (gxpath.c)

    Adds gs_glyphpath, like charpath but taking a glyph rather than a string of
    character codes.  (gschar.h, gschar.c)

    Adds an internal concept of a "null color", a color that doesn't actually
    mark any pixels.  (gscolor.h, gsdcolor.h, gxdcolor.h, gscolor.c, gxdcolor.c)

    Takes the next incremental steps towards passing images through the band
    list:
    	- Implements the ability to pass some color mapping information
    (transfer functions, black generation, undercolor removal) through the band
    list.  (gxclist.h, gxclimag.c, gxclist.c, gxclread.c)

## Version 4.33 (limited) (11/6/96)

This release fixes yet another obscure bug in the recently rewritten fast loops for image rendering. (These loops have caused more problems than any other single module of the entire library.) It also adds preliminary support for CID-keyed fonts (CIDFonts only, not CMaps yet) and some library extensions for supporting HP-GL/2.

### Documentation

    Adds considerable new material to the C style document.  (c-style.txt)

    Changes -cckr to -ansi in the SGI build procedure.  (make.txt)

    Corrects an error in the description of the .type42execchar operator.
    (gs_typ42.ps)

### Procedures

    Fixes bugs:
    	- The 'man' pages were installed in the documentation directory as
    well as in the man directory.  (unix-end.mak)

### Interpreter

    Adds support for CID-keyed fonts.  There is no CMap support yet, and some
    things are done with hacks.  (int.mak, gs_cidfn.ps, gs_cmap.ps, ichar.h,
    zchar.c, zchar2.c, zchar42.c, zfont2.c, zfont42.c, zcid.c)

    Adds operators for accessing the new dash adaptation and dot length
    parameters in the graphics state.  (gs_init.ps, zgstate.c)

### Library

    Fixes bugs:
    	- The fast case of monobit image rendering could overwrite memory.
    (gximage1.c)
    	- The new fast implementation of rectfill didn't check for
    fixed-point overflow.  (gsdps1.c)
    	- Internally, fonts with no name all appeared to have the same name,
    possibly confusing the xfont machinery.  (gxccman.c)
    	- A cast to remove const was omitted, upsetting some compilers.
    (gximage1.c)
    	- The driver's stroke_path routine was not called if the logical
    operation was not the default one.  (gxpaint.c)

    Adds support for CID-keyed fonts.  (gsccode.h, gxfont.h)

    Adds a new "dash pattern adaptation" flag in the imager state.  When this
    flag is set and a dash pattern is in effect, each line segment will receive
    an integral number of repetitions of the dash pattern (if necessary, rounded
    up).  (gsline.h, gxline.h, gsline.c, gsstate.c, gxpdash.c)

    Adds a new "dot length" parameter to the imager state.  If this parameter is
    non-zero, it gives a length for rendering dots (zero-length lines).  See
    language.txt for details.  (gsline.h, gxline.h, gsline.c, gsstate.c,
    gxstroke.c)

    Extends band lists so they can handle dash pattern adaptation and dot
    length.  (gxcldev.h, gxclpath.h, gxclpath.c, gxclread.c)

    Adds a floating point emulator to allow more realistic profiling of
    configurations without a FPU.  (gsfemu.c)

## Version 4.32 (limited) (11/1/96)

This fixes a couple more bugs, most notably the infamous "pixel stripe" bug.

### Documentation

    Fixes bugs:
    	- The documentation said that Ghostscript could not interpret
    encrypted PDF files.  (language.txt)
    	- A number of Ghostscript's extensions to the PostScript language
    were missing.  (language.txt)

### Drivers

    Fixes bugs:
    	- A compiler complained about initializing an unsigned variable with
    a negative value.  (gdevx.c)
    	- An off-by-1 allocation error could cause memory overwriting.
    (gdevepsc.c)

### Platforms

    Declares a pointer 'const' that is actually only used for reading.
    (gp_unifs.c)

### Fonts

    Fixes bugs:
    	- The code for adding nominal UnderlinePosition and
    UnderlineThickness entries to FontInfo assumed (incorrectly) that all Type 1
    fonts had FontBBox entries.  (gs_type1.ps)

    Brings CIDFont support closer to reality.  It doesn't work yet, though.
    (gs_cidfn.ps, gs_fonts.ps, gs_init.ps, gs_res.ps, gs_typ42.ps)

### Interpreter

    Removes a redundant implementation of initgraphics.  (gs_init.ps)

    Speeds up rectfill a little for the common case (4 numbers on the stack).
    (zdps1.c)

### Library

    Fixes bugs:
    	- Zero-width, 1-bit-deep, landscape or portrait images could
    overwrite memory ad lib.  (gximage1.c)
    	- A procedure was declared 'static' inconsistently, upsetting many
    compilers (but not gcc, which, in contradiction to the ANSI standard,
    doesn't check this properly).  (gxcpath.c)
    	- A local variable was initialized with a value computed from a
    variable that hadn't been set yet, leading to possibly incorrect coloring of
    the first run of pixels in images with 12 bits per sample.  (gximage4.c)
    	- A compiler complained about initializing an unsigned variable with
    a negative value.  (shcgen.c)
    	- A rounding problem could produce a vertical stripe of 1 (or on
    very large images possibly more) incorrect pixels at the right edge of a
    1-bit-deep image.  (gxdda.h, gximage1.c)

    Speeds up gs_rectfill substantially for the portrait/landscape case with a
    rectangular clipping region.  (gsdps1.c)

    Adds a parameter so we can include gx_line_params in subclasses.  (gzline.h)

## Version 4.31 (limited) (10/27/96)

This is primarily a bug fix release for 4.30, which we had hoped wouldn't be necessary....

### Documentation

    Fixes bugs:
    	- The comment describing the order of coefficients in a CTM written
    on the band list was wrong.  (gxclpath.h)

### Procedures

    Fixes bugs:
    	- bug-form.txt wasn't installed by 'make install'.  (unix-end.mak)
    	- The default flags in ugcclib.mak didn't take the gcc code
    generation bug into account.  (ugcclib.mak)

### Platforms

    Fixes bugs:
    	- MetroWerks CodeWarrior predefines true and false, causing
    compilation errors on the Mac.  (stdpre.h)

### Interpreter

    Updates code for the change in the ENUM_PTR macros.  (iscan.c)

    Changes the allocator to keep track of "lost" ref space separately, to allow
    an independent check on its activities.  (gxalloc.h, ialloc.c, isave.c)

    Changes the garbage collector API slightly to allow implementation of the
    API in applications other than PostScript interpreters.  (ivmspace.h,
    ireclaim.c, igc.c)

### Interpreter (PDF)

    Implements the PDF 1.1 BX and EX operators.  (pdf_base.ps, pdf_main.ps)

### Streams

    Fixes bugs:
    	- Some (harmless) pointer incompatibilities upset some compilers.
    (szlibd.c, szlibe.c)

    Updates code for the change in the ENUM_PTR macros.  (stream.c)

### Library

    Fixes bugs:
    	- A label in the ENUM_PTR procedure generating macros was often not
    referenced, leading to compiler warnings.  (gsstruct.h, gxxfont.h,
    gdevmem.c, gschar.c, gscolor2.c, gsdevice.c, gsfont0.c, gsht.c, gsstate.c,
    gxcpath.c, gximage.c)
    	- Using the gstate version of setflat rather than the imager version
    caused compiler warnings (and, in some cases, errors).  (gstype1.c)
    	- Non-standard ImageMatrix values for banded images didn't work.
    (This wasn't actually used.)  (gxclread.c)
    	- imagemask with a halftone and portrait orientation colored some
    inappropriate pixels.  (bug introduced in 4.30) (gximage2.c)
    	- When banding, if a character straddled a band boundary the first
    time it occurred, all occurrences of it were clipped.  (bug introduced in
    4.2x or 4.30) (gxclimag.c)
    	- Degenerate clipping rectangles sometimes got turned into
    non-degenerate ones by swapping the min and max coordinates.  (gxcpath.c)
    	- Resizing an object either allocated a new object unnecessarily
    (performance bug only), or in very rare cases could corrupt memory.
    (gsalloc.c)
    	- Very small objects didn't get put on a free list when freed.
    (Performance bug only.) (gsalloc.c)
    	- Some pointers were incorrectly declared 'const', upsetting some
    compilers.  (gxclread.c)

    Adds more tracing output for -ZL.  (gxclread.c)

    Changes the -Za tracing output slightly to aid mechanical analysis of
    allocation traces: allocation events now always include a '+', deallocation
    events always include a '-', and the address is always the address of the
    object data and not the header.  (gsalloc.c, gsmemory.c)

    Changes the allocator to keep track of "lost" object and string space
    separately, to allow an independent check on its activities.  (gxalloc.h,
    gsalloc.c)

    Changes the allocator to use 'memmove' in an obvious place.  (gsalloc.c)

    Provides a garbage collector API at the library level to allow
    implementation of the API in applications other than PostScript
    interpreters.  (gsgc.h)

## Version 4.30 (limited) (10/23/96)

The main purpose of this release is to implement a substantial change in the "high level" image API, after which we believe this API will be stable.

### Documentation

    Documents the changes in the begin_image and image_data device procedures.
    (drivers.txt)

### Drivers

    Speeds up the PDF writer a little by reducing the amount of allocation,
    which was causing very frequent garbage collections.  (gs_pdfwr.ps,
    gdevpdft.c)

    Updates the PDF writer for the change in begin_image/image_data.
    (gdevpdfi.c)

### Platforms

    Fixes bugs:
    	- Some versions of the SGI IRIX compiler have a bug that causes them
    to try to expand macros that require arguments even when the macro name
    isn't followed by a left parenthesis.  (gdevsgi.h, gdevsgi.c)
    	- The IBM RS6000 compilers now provide <stdlib.h>, so our
    definitions of malloc and free caused a conflict.  (malloc_.h)

### Fonts

    Fixes bugs:
    	- Many Fontmaps included obsolete references to an old
    Helvetica-Narrow font.  (Fontmap.*)

    Makes the GS_FONTPATH directory scanner a little more liberal about what
    files it examines: it will now examine any file whose first line begins with
    %!PS-Adobe or %!FontType.  (gs_fonts.ps)

    To match an apparent Adobe convention, augments findfont so that if a font
    isn't in the Fontmap, it will try to load a file whose name is the same as
    the font name.  (gs_fonts.ps)

    To make some questionable Apple font inquiry code work, augments the
    FAKEFONTS facility so that it sets the FontType of fake fonts to 1.
    (gs_fonts.ps)

### Interpreter

    Fixes bugs:
    	- .checkpassword, .putdeviceparams, .putdevparams, setsystemparams,
    and setuserparams didn't free the results byte array, causing a memory leak
    (until the next garbage collection).  (zdevice.c, ziodev.c, zusparam.c)

### Library

    Fixes bugs:
    	- The code for emulating floating point multiplication with
    conversion to fixed point didn't detect overflow correctly, which could
    produce incorrect results instead of a limitcheck.  (gsmisc.c)
    	- A macro cast a pointer incorrectly, leading to spurious compiler
    warnings.  (gxfixed.h)
    	- The code for emulating fixed-to-float conversion computed the
    exponent incorrectly.  (gsmisc.c)
    	- The algorithm for advancing a DDA a given number of steps (not
    actually used anywhere before this version) was wrong.  (gxdda.h)
    	- The clipping box returned by clipping devices was incorrect,
    causing parts of the page to disappear.  (bug introduced in 4.20)
    (gxcpath.c)

    Changes the begin_image and image_data device procedures:
    	- begin_image now takes an optional subrectangle instead of a set of
    shape flags.
    	- image_data now always takes complete rows of pixels, takes a
    source X offset, and returns 1 when it has received all the data.

    The change in begin_image and image_data is a NON-BACKWARD-COMPATIBLE CHANGE
    IN A PUBLIC INTERFACE; however, this interface was still designated "subject
    to change", per the notes for release 3.67 and the documentation in
    drivers.txt.  (gsiparam.h, gxclpath.h, gxdda.h, gxdevice.h, gximage.h,
    gdevbbox.c, gdevnfwd.c, gsimage.c, gxclimag.c, gxclread.c, gximage.c,
    gximage?.c)

## Version 4.21 (limited) (10/17/96)

The purpose of this release is to fix bugs reported in 4.0x, 4.10, and 4.20.

### Documentation

    Fixes bugs:
    	- The Ghostscript man page had a .TH in the middle.  (gs.1)

### Procedures

    Fixes bugs:
    	- The shared version of zlib was always called libgz; on most
    systems, it is now called libz (but not on Red Hat Linux, where libz is a
    library for dealing with time zones).  (*.mak, gs.mak, libpng.mak, zlib.mak)
    	- The pdf2dsc.1 man page wasn't installed on Unix systems.
    (unix-end.mak)
    	- font2c generated procedures named gsf_xxx, but genconf assumed
    they were named gs_f_xxx.  (int.mak)

### Drivers

    Updates the user-contributed LBP-8II driver to correct unspecified problems.
    (gdevlbp8.c)

    Adds a user-contributed driver for Avance Logic SuperVGA cards.
    (gdevsvga.c, devs.mak)

### Platforms

    Fixes bugs:
    	- On Windows NT, a 32-bit parameter was truncated to 16 bits,
    preventing drawing of scroll bars of the image window when the window is
    uncovered.  (dwimg.cpp)

### Fonts

    Fixes bugs:
    	- The free URW Grotesk and Antiqua fonts were omitted from the
    distribution.

### Interpreter

    Fixes bugs:
    	- Defining a new global instance of a built-in resource
    (ColorRendering, ColorSpace, Form, Halftone, Pattern, ProcSet) caused an
    invalidaccess error.  (gs_res.ps)
    	- pathbbox with no current path left an extra item on the stack when
    the error occurred.  (gs_init.ps)
    	- findresource for an undefined resource instance didn't preserve
    the contents of the stack.  (gs_res.ps)

    Adds a new file providing a procedural interface with a very rudimentary
    form of job encapsulation.  (gserver.c)

    Changes the initial value of MaxOpStack to 20000, for the sake of a few
    badly-behaved files.  (gs_init.ps, pdf_base.ps)

### Library

    Fixes bugs:
    	- If the image operators failed to allocated their bookkeeping
    structure, the result was a crash rather than VMerror.  (gximage.c)
    	- gx_default_fill_triangle (currently used only to implement the
    fastest case of stroke) had a typo that could cause a numeric exception or
    incorrect output, and another typo that could produce incorrect output.
    (gdevddrw.c)
    	- When banding, if the first occurrence of a character fell partly
    off the page, all occurrences of that character on the page could be clipped
    or mangled.  (gxclbits.c, gxclimag.c)
    	- When testing whether it's worthwhile compressing a bitmap for
    banding, the compressor was allowed to generate a lot more output than
    needed to make the test.  (gxclbits.c)
    	- Certain cases of unrotated gray-scale images dropped the first or
    last pixel of each scan line.  (gximage2.c)
    	- In rare cases, a run of pixels in a image could get erroneously
    displayed in the same color as the previous run, because of a cache
    bookkeeping bug.  (gximage3.c)
    	- The sample driver for the library had gotten inconsistent with a
    header file.  (gslib.c)
    	- A declaration was followed by an extraneous semicolon, which upset
    some compilers.  (gxht.h)
    	- Missing parentheses caused a test for thin lines to be incorrect.
    (gxstroke.c)

## Version 4.20 (limited) (10/13/96)

This release has internal changes for future support of banded image processing, but no externally visible changes. Its primary purpose is to incorporate speedups for clipped images. It does *not* incorporate fixes for all problems reported in 4.0x or 4.10.

### Documentation

    Documents the new get_clipping_box device procedure.  (drivers.txt)

### Procedures

    Fixes bugs:
    	- There were many, many minor inconsistencies between the makefiles
    and the source code.  (We finally have an automated tool to detect these.)
    (devs.mak, int.mak, lib.mak, unixtail.mak; gsutil.c, zwppm.c)
    	- Some makefile rules weren't properly terminated by a blank line.
    (lib.mak)

### Utilities

    Fixes bugs:
    	- The comments in gslp.ps had gotten out of date.  (gslp.ps)

    Adds --no-eject-file and --no-eject-formfeed switches to gslp.ps, to allow
    packing files in multi-column printouts.  (gslp.ps)

### Drivers

    Adds a user-contributed driver for the Epson LP-8000 laser printer.
    (gdevlp8k.c)

    Adds a DisplayMode parameter to the vgalib device.  (gdevvglb.c)

    Removes the requirement of typing a character at the end of each page using
    the vgalib driver.  THIS IS A USER-VISIBLE, NON-BACKWARD-COMPATIBLE CHANGE.
    (gdevvglb.c)

### Interpreter

    Updates code to accommodate the new get_clipping_box device procedure.
    (zupath.c)

### Library

    Fixes bugs:
    	- When a CTM was passed through the band list, it didn't get
    translated to match the band coordinate system.  (This had no effect,
    because the translation part of the CTM was never used.)  (gxclread.c)

    Adds a ',' debugging switch to disable high-level operations when banding.
    (gxclpath.c)

    Adds an optional get_clipping_box device procedure, so that filling and
    stroking can clip more aggressively.  (gdevmem.h, gdevprn.h, gxdevice.h,
    gxpaint.h, gxpath.h, gzacpath.h, gdevdflt.c, gdevht.c, gdevnfwd.c,
    gxacpath.c, gxclip2.c, gxclist.c, gxcpath.c, gxpcmap.c, gxfill.c,
    gxstroke.c)

    Speeds up clipped filling and stroking, by checking against the device
    clipping box.  (gxfill.c, gxstroke.c)

    Adds the ability to clip with a rectangle a clipping path being accumulated,
    and uses it to do more aggressive clipping when banding.  (gzacpath.h,
    gxacpath.c, gxclread.c)

    Speeds up clipping of objects lying partly above or below the clipping
    region.  (gxcpath.c)

    Speeds up clipping vertically-oriented objects (such as 90 degree rotated
    images or vertical rectangles) with convex clipping regions, by checking for
    vertical rectangles contained in multiple clipping rectangles.  (gxcpath.c)

    Speeds up the handling of 90 degree rotated gray-scale images.  (gximage2.c)

    Enhances the band list so that it can contain commands for a range of bands,
    not just a single band or all bands.  (gxcldev.h, gxclist.h, gxclbits.c,
    gxclist.c, gxclread.c)

    Adds an operation to the DDA structure, for eventual support of clipped
    images.  (gxdda.h)

    Factors out some macros useful for generating bit-transformation tables.
    (gsbittab.h, gsbittab.c, gsflip.c)

## Version 4.10 (limited) (9/25/96)

This release adds local garbage collection, and a number of performance improvements for garbage collection in general. We will support it for one or two OEMs, but it is not a public release.

### Documentation

    Moves documentation for all releases before 4.0 to history3.txt.  (NEWS,
    history3.txt)

### Utilities

    Fixes bugs:
    	- pdf2dsc.ps didn't have a proper license notice.  (pdf2dsc.ps)

### Drivers

    Adds a psgray driver, like psmono, to produce 8-bit gray PostScript (level
    1) images.  (devs.mak, *.mak, gdevpsim.c)

    Changes the psmono driver to allow runs of up to 255 repeated bytes.
    (gdevpsim.c)

### Interpreter

    Fixes bugs:
    	- setdevice erased the page even if this wasn't necessary.
    (zdevice.c)

    Speeds up the garbage collector, primarily by speeding up pointer
    relocation.  (int.mak, ipacked.h, iref.h, ialloc.c, igc.c, igcref.c)

    Actually implements local garbage collection.  (igc.h, ivmspace.h, igc.c,
    igcref.c, igcstr.c, ireclaim.c)

    Adds some additional error checking for the -Z? switch.  (ilocate.c)

    Moves a utility for color mapping from the interpreter to the library.
    (icolor.h, zcolor.c)

    Adds a MinScreenLevels user parameter.  (zusparam.c)

### Interpreter (PDF)

    Adds partial support for the PDF 1.2 gs operator, reverse engineered from a
    PDF 1.2 file.  (pdf_draw.ps)

### Library

    Fixes bugs:
    	- The test for "thin" stroked lines incorrectly claimed some
    non-thin lines were thin.  (gxstroke.c)
    	- The computations for halftone cells didn't work for non-square
    pixels.  (gxdht.h, gsht.c, gsht1.c, gshtscr.c)

    Speeds up the garbage collector a little.  (gsstruct.h, gxalloc.h,
    gxfcache.h, gsfont.c)

    Replaces references to private statically allocated color spaces with
    references to shared dynamically allocated ones, which are guaranteed to be
    fully filled-in.  (gscie.c)

    Moves a utility for color mapping from the interpreter to the library.
    (gxfmap.h, gxcmap.c)

    Makes available an imager analogue of setmatrix.  (gscoord.h, gscoord.c)

    Adds a parameter to control the minimum number of halftone screen levels.
    If a halftone cell has fewer pixels than this number, it will be replicated
    (similar to what AccurateScreens does) until the replicated screen has
    enough levels.  (gxht.h, gshtscr.c)

## Version 4.03 (9/23/96)

This was an emergency re-release of 4.02 to fix the stdin redirection problem. It has essentially no other changes.

### Documentation

    Fixes bugs:
    	- Solaris 2.x has /usr/ucb/install, not installbsd.  (make.txt)

    Updates current.txt to mention the ability to share libpng and libgz.
    (current.txt)

### Procedures

    Fixes bugs:
    	- A rule assumed that the makefile was named `makefile'.
    (unixtail.mak)

### Drivers

    Fixes bugs:
    	- The stcolor drivers had an off-by-1 error that could cause them to
    write into unallocated memory.  (gdevstc.c)
    	- The Imagen driver wouldn't compile with gcc.  (gdevimgn.c)

### Fonts

    Fixes bugs:
    	- The Solaris fontmap had gotten out of date.  (Fontmap.Sol)

### Streams

    Fixes bugs:
    	- The test for stdin being non-seekable could leave the file error
    flag set, which caused an infinite loop when trying to read from the file
    later.  (sfile.c, sfileno.c)

## Version 4.02 (9/19/96)

This release fixes a few more bugs, and adds the ability to read encrypted PDF files and some PDF 1.2 files.

This release was withdrawn after a few days because the stdin redirection fix, which was made at the last minute, cause Ghostview to hang.

### Documentation

    Fixes bugs:
    	- The list of required support files was incorrect.  (install.txt)
    	- The descriptions of file name lookup weren't accurate.  (use.txt)
    	- A J should have been an H.  (gxbitmap.h)

    Updates the documentation about encrypted PDF files.  (new-user.txt)

    Documents what the 13 base PDF fonts are.  (ps2pdf.txt)

    Fixes a tiny typo.  (c-style.txt)

    Adds a user-contributed man page for the new pdf2dsc script.  (pdf2dsc.1)

    Updates the government restricted rights notice in the Aladdin Ghostscript
    Free Public License.  (PUBLIC)

    Adds the URL of test files to the bug report form.  (new-user.txt)

    Puts the bug reporting form in a separate file.  (readme, bug-form.txt,
    new-user.txt)

    Notes that map_xxx_color procedures should not return gx_no_color_index.
    (drivers.txt)

    Notes that Ghostscript supports the Flate filters.  (language.txt)

    Documents the use of the system libpng and zlib.  (make.txt, gs.mak)

    Notes that Borland C++ 5.0 and 5.01 will not compile Ghostscript correctly.
    (make.txt)

### Procedures

    Fixes bugs:
    	- Using both DELAYBIND and SAFER caused problems.  (pstotext uses
    DELAYBIND.)  (gs_init.ps)

### Utilities

    Fixes bugs:
    	- Some pdf2ps machinery interfered with the PDF interpreter.
    (pdf_2ps.ps, pdf_main.ps)
    	- In the output of pdf2ps, page numbers in link destinations were
    too high by 1.  (pdf_main.ps)
    	- viewpbm didn't handle value ranges other than [0..255] correctly.
    (viewpbm.ps)

    Adds a user-contributed shell script to invoke pdf2dsc.ps.  (pdf2dsc,
    unix-end.mak)

    Adds a switch to the genconf utility to set the prefix for generated
    procedure names.  (genconf.c)

    Adds the option of using system libraries (possibly shared) for libpng
    and/or zlib.  (*head.mak, msc*.mak, os2.mak, tccommon.mak, wccommon.mak;
    libpng.mak, zlib.mak)

### Drivers

    Fixes bugs:
    	- The X11 display devices ignored the -DA4 compile-time option.
    (gdevx.c)
    	- The garbage collector could scramble the state of the CGM drivers.
    (gxdevice.h, gdevcgm.c)
    	- An identifier of more than 31 characters upset the VAX DEC C
    compiler.  (gdevcgml.h, gdevcgml.c)
    	- In case of an error in trying to set the CoreDistVersion distiller
    parameter, a variable could be used without initialization.  (gdevpdfp.c)
    	- When DEBUG is selected, the X Windows driver referenced _Xdebug,
    which is not defined in (at least the VMS version of) DECWindows.  (x_.h,
    gdevxini.c)
    	- Some map_cmyk_color implementations could return "transparent".
    (gdevbit.c)
    	- Setting GraphicsAlphaBits or TextAlphaBits in the P*M drivers
    caused an error.  (gdevpbm.c)
    	- If a user cancelled printing under MS Windows, a confusing error
    resulted, and a temporary file wasn't deleted.  (gdevwpr2.c)
    	- The map_color_rgb procedure for the bit devices produced incorrect
    results.  (This probably had no effect in practice.)  (gdevbit.c)
    	- The os2prn device produced incorrect output.  (gdevos2p.c)
    	- The OS/2 PM device didn't detect PM applications correctly.
    (gdevpm.c)
    	- The MS Windows printer driver didn't automatically detect the
    printer's color capabilities.  (gdevwpr2.c)
    	- The BJC-610 driver didn't print at 720 dpi.  (gdevcdj.c)
    	- The static prototypes of many devices didn't include the far_data
    keyword.  (gdev3852.c, gdev4081.c, gdevbgi.c, gdevcgm.c, gdevht.c,
    gdevimgn.c, gdevl256.c, gdevmrop.c, gdevn533.c, gdevnfwd.c, gdevnp6.c,
    gdevo182.c, gdevpcfb.c, gdevpdf.c, gdevpe.c, gdevpm.c, gdevs3ga.c,
    gdevsnfb.c, gdevsppr.c, gdevsun.c, gdevsvga.c, gdevtknk.c, gdevvglb.c,
    gdevwddb.c, gdevwprn.c, gdevx.c, gdevxalt.c)
    	- The (original) deskjet driver collapsed print lines towards the
    left margin.  (gdevdjet.c)

    Adds to the pgm/pgnm/ppm/pnm[raw] drivers the ability to set the maximum
    pixel value, by setting any of the Gray/Red/Green/BlueValues device
    parameters.  (gdevpbm.c)

    Adds pkm[raw] drivers, which do all their internal computations in CMYK and
    convert the data to RGB as they write the file.  (gdevpbm.c)

### Platforms

    Fixes bugs:
    	- The VMS script referred to old versions of the third-party
    libraries.  (vms.mak)
    	- Under VMS with DEC C, attempting to open a new file fails.
    (gp_vms.c)
    	- If you tried to print (gp_printfile) under Windows on a system
    with no printers installed, Ghostscript caused a GPF.  (gp_mswin.c)

    Restores support for a non-DLL MS Windows platform.  (bcwin32.mak,
    dwnodll.cpp)

    Adds a new MS Windows DLL call, gsdll_get_bitmap.  (gsdll16.def,
    gsdll32.def, dll.txt, gdevwdib.c)

    Fixes a variety of other small Windows- and OS/2-related problems, mostly
    related to printing.  (gp_mswin.h, dpmainc.c, dwmain.cpp, dwmainc.cpp,
    gdevmswn.c, gdevpm.c, gdevwpr2.c, gp_mswin.c)

### Interpreter

    Fixes bugs:
    	- The value of /newerror in $error was true at the end of
    initialization.  We now reset it after each internal use of stopped if
    necessary.  (gs_dps1.ps, gs_fform.ps, gs_fonts.ps, gs_init.ps, gs_pdf.ps,
    gs_res.ps, gs_type1.ps)
    	- setpagedevice (and finddevice) didn't recognize Default.
    (gs_init.ps)
    	- When running with -dNODISPLAY, calling gssetresolution would cause
    a crash.  (gs_init.ps)
    	- A particular combination of save, .forgetsave, and garbage
    collection could cause a memory access error in restore.  (isave.c)
    	- Some references to systemdict were affected if a user redefined
    the name /systemdict.  (gs_cmdl.ps, gs_fonts.ps, gs_kanji.ps, gs_dps1.ps,
    gs_init.ps, gs_res.ps, gs_statd.ps, gs_type1.ps)
    	- The insideness testing operators caused an invalid memory access.
    (drivers.txt, zupath.c)
    	- If a readline reached an input buffer boundary between the \r and
    \n of a 2-character EOL, an error could occur.  (zfileio.c)
    	- setdevparams caused an error.  (gs_lev2.ps)

    Changes file names beginning with ./ or ../ so they are recognized as
    "absolute" and not subject to the search path.  (gp_dosfs.c, gp_ntfs.c,
    gp_os2.c, gp_unifn.c)

    Changes the exit code for -h or --help from 0 to 1, so an invoking program
    will keep the output around for the user to look at.  (imainarg.c)

    Adds the FlateEncode and FlateDecode filters; adds PNG pixel prediction to
    the LZW filters.  These additions are required for PDF 1.2 and will be part
    of PostScript Level 3.  (int.mak, lib.mak, zfdecode.c, zfilter2.c, zfzlib.c,
    zfpngp.c [deleted])

### Interpreter (PDF)

    Fixes bugs:
    	- The copyright notices on some files didn't mention the Aladdin
    free license.  (pdf_*.ps)
    	- Some references to systemdict were affected if a user redefined
    the name /systemdict.  (pdf_font.ps)
    	- The value of /newerror in $error was true at the end of
    initialization.  We now reset it after each internal use of stopped if
    necessary.  (pdf_main.ps)
    	- stdin redirection failed for PDF files even if the new stdin was
    seekable.  (pdf_main.ps)
    	- The Rotate key rotated pages in the wrong direction.
    (pdf_main.ps)

    Adds a minimal "security socket" to the interpreter.  This does not include
    any actual decryption code; such code is available elsewhere (see
    new-user.txt).  (int.mak, pdf_base.ps, pdf_main.ps, pdf_sec.ps)

    Adds a PDF 1.2 capability:
    	- The destination in a Dest array can be a page number as well as a
    page object.  (pdf_main.ps)

### Streams

    Fixes bugs:
    	- stdin was assumed to be non-seekable.  (sfile.c, sfileno.c)

### Library

    Fixes bugs:
    	- Garbage collection could corrupt a pointer in Type 0 fonts.
    (gxfont0.h, gsfont0.c)
    	- When applying hints to a Type 1 font outline, the last point could
    sometimes get moved twice, causing output anomalies.  (gxhint3.c)
    	- An #include needed for debugging was missing.  (gxcmap.h)
    	- Graphics states included a no-longer-used private color space
    object.  (gsstate.c)
    	- Images could get clipped randomly in the X direction.  (I don't
    understand why this problem hasn't shown up more often, since it's been
    there since release 4.00.)  (gximage.c)
    	- The arct and arcto operators failed to draw the line to the
    starting point of the arc.  (bug introduced in 4.01) (gspath1.c)
    	- Prefix subclasses of simple structures caused an invalid memory
    access.  (gsstruct.h)
    	- The variable fheight was sometimes unused.  (gstype1.c)
    	- igcd and imod didn't have prototypes in an appropriate header
    file, and were declared extern in several places.  (gsdcolor.h, gsline.h,
    gxarith.h, gxdht.h, gsht.c, gshtscr.c, gsimage.c, gsline.c, gstype1.c,
    gxclimag.c)
    	- When using a non-identity RenderTable in a CIE rendering
    dictionary, all colors came out too light.  (gscie.c)
    	- When using anti-aliased graphics, stroked lines were rendered too
    thin.  (gspaint.c)
    	- The default map_cmyk_color implementations could return
    "transparent".  (gxcmap.c)
    	- The number of bits of alpha requested when rendering anti-aliased
    characters could exceed 4.  (gschar.c)
    	- Multi-screen halftones could cause errors or infinite looping when
    banding.  (This problem predates 4.0; I don't know why it didn't show up
    before.)  (gxcldev.h, gxclist.c, gxclread.c)
    	- Skewed or rotated gray-scale images, or masks with a halftoned
    color, omitted one line of pixels and displaced the image by one pixel.
    (gximage2.c)

    Adds an implementation of realloc, for systems that don't have one that
    works.  I don't know how to determine this automatically, so for the moment,
    the code uses our own implementation on Linux (where realloc is known to be
    broken, at least in some releases) and nowhere else.  (malloc_.h,
    gsmemory.c, gsmisc.c)

    Removes the "OLD" algorithms from the Type 1 hinting source code, since they
    are no longer executed.  (If necessary, they can be retrieved from an older
    version.)  (gxhint3.c)

## Version 4.01 (7/10/96)

This fixes a few minor bugs discovered since the 4.0 release.

### Documentation

    Fixes bugs:
    	- An installation directory name was wrong.  (make.txt,
    unix-lpr.txt)
    	- A URL was wrong.  (devices.txt)
    	- A reference to use.doc hadn't been updated.  (gs.1)
    	- Some references to /usr/local/lib hadn't been updated.  (gs.1)
    	- The NEWS file and history* files still referred to *.doc rather
    than *.txt.  (NEWS, history*.txt)

    Adds a note about compilation on Digital Unix.  (make.txt)

    Clarifies that calling gs_exit calls gs_finit automatically.  (imain.h)

    Adds a pointer to the PDF encryption patch.  (Ridiculous U.S. export control
    laws don't allow including the patch itself in the main fileset.)
    (new-user.txt)

    Adds a help file for VMS.  (gs-vms.hlp)

### Procedures

    Fixes bugs:
    	- vms.mak had gotten out of sync with the makefiles (again).
    (vms.mak)
    	- DEVICE{WIDTH,HEIGHT}POINTS didn't override PAPERSIZE.
    (gs_init.ps)
    	- The Microsoft C makefiles had gotten out of date.  (msc.mak)

    The (few) GNU-Licensed drivers were accidentally omitted from the fileset.

    Modifies a makefile for greater reusability.  (watclib.mak)

    Adds a 'debug' target for making Unix debugging configurations.
    (unix-end.mak)

### Utilities

    Fixes bugs:
    	- Some uses of 'run' should be changed to runlibfile.  (bdftops.ps,
    impath.ps, markhint.ps, packfile.ps, showchar.ps, waterfal.ps, wftopfa.ps,
    wrfont.ps)
    	- Some debugging code hadn't been removed.  (gslp.ps)

    Adds a new utility, viewcmyk.ps, for viewing 4-bit CMYK data.  (psfiles.txt,
    unix-end.mak, viewcmyk.ps)

    Improves pdf2dsc by including Title and CreationDate DSC comments (these are
    displayed by Ghostview) and reducing the size of typical output files by a
    factor of about 3.  (pdf2dsc.ps)

    Incorporates major changes (claimed to be improvements) to ps2ascii
    contributed by a user.  If you have problems with it, please contact him,
    not Aladdin.  (ps2ascii.ps)

### Platforms

    Fixes bugs:
    	- The X value of a bounding box could be computed incorrectly.
    (gdevbbox.c)

### Platforms

    Fixes bugs:
    	- The Windows DLL sometimes didn't clean up properly.  (dll.txt,
    dpmainc.c, dwdll.cpp, dwmain.cpp, dwmainc.cpp, gsdll.c, gsdll.h)

### Interpreter

    Fixes bugs:
    	- Reading from a filter could hang forever, because a buffer was
    allocated 1 byte too small.  (zfilter.c)
    	- The search path could become garbage under some circumstances.
    (imain.c)
    	- A dangling reference to a stack-allocated variable could corrupt
    memory if a client mixed interpreter calls and direct C calls.  (interp.c)
    	- Printing an object to a procedure-based filter could cause an
    invalid memory access.  (zfileio.c)

### Library

    Fixes bugs:
    	- Setting parameters for an unopened device could cause an access
    error or invoke the wrong put_params procedure.  (gsdparam.c)
    	- Reading from a filter could hang forever, because a buffer was
    allocated 1 byte too small.  (stream.h)
    	- If the current device was the nullpage device, doing a [g]save,
    selecting a different device, and doing a [g]restore caused an error.
    (gsdparam.c)

    Adds the ability to append arcs without the initial lineto, for PCL
    emulation.  (gspath.h, gspath1.c)

## Version 4.0 (6/28/96)

This is the first public release since 3.53, with a few more last-minute patches beyond 3.70.

### Documentation

    Fixes bugs:
    	- Many makefiles still referred to .doc files rather than .txt.
    (cfonts.mak, devs.mak, gs.mak, int.mak, libpng.mak, unix-end.mak, watc.mak,
    watcwin.mak, wccommon.mak, zlib.mak)
    	- Some FONTPATH-related information was out of date.  (use.txt)
    	- The installation directory for fonts was incorrect.  (install.txt)
    	- The libpng and zlib versions were out of date.  (libpng.mak,
    zlib.mak)
    	- Some information about GSview was incorrect or incomplete.
    (new-user.txt)
    	- make.txt said it described installation as well as building.
    (make.txt)

    Notes that the current release of zlib won't compile and link correctly with
    Sun cc.  (make.txt)

    Adds a little more detail to the C style document.  (c-style.txt)

### Procedures

    Fixes bugs:
    	- Some documentation files weren't installed.  (unix-end.mak)
    	- Some dependencies were incorrect.  (bcwin32.mak)
    	- 'make begin' and 'make clean' deleted too many and/or the wrong
    files.  (bcwin.mak, bcwin32.mak)
    	- libpng.mak didn't work with libpng version 0.89c.  (libpng.mak)
    	- -d<var>=<name> was equivalent to -d<var>=/<name>, and there was no
    way to set a variable to true, false, or null.  (use.txt, gs_init.ps,
    iinit.c, imainarg.c)

    Removes the modules.lis file, which is no longer used.

    Undoes detecting automatically the need to run tar_cat -- the mechanism
    didn't work, and caused confusion.  (unix-end.mak)

    Updates the makefiles to libpng version 0.89, but allows them to work with
    either 0.88 or 0.89.  (*.mak)

### Utilities

    Fixes bugs:
    	- Showing the details of a protected font caused an error.
    (markhint.ps)

### Drivers

    Fixes bugs:
    	- A copyright notice was wrong.  (gs_pdfwr.ps)
    	- PDF link annotations could get written with two Dest keys.
    (gdevpdfm.c)
    	- MakeProcInstance and FreeProcInstance were called on platforms
    where it wasn't appropriate.  (gdevwpr2.c, gdevwprn.c, gp_mswin.c)
    	- On X servers that return very large values for the "virtual
    screen" size in millimeters but correct values for the screen size in
    pixels, a rangecheck could occur.  (gdevxini.c)
    	- The bounding box device could return garbage if stroke or fill was
    ever invoked with an empty path.  (gdevbbox.c)

    Replaces the LBP8 driver with a revised one contributed by a user.
    (gdevlbp8.c, devs.mak)

### Platforms

    Fixes bugs:
    	- Some Windows menu parameters were incorrect.  (gsdll16.rc,
    gsdll32.rc)

### Interpreter

    Fixes bugs:
    	- .getdevparams sometimes returned duplicate entries for /Type.
    (ziodev2.c)
    	- File names weren't parsed or concatenated properly on all
    platforms.  (gs_fonts.ps, zfile.c)
    	- Filter lookahead caused problems with special files.  (zfproc.c)
    	- If a TransformPQR procedure in a CIE color rendering dictionary
    didn't pop its 4 array arguments, an error occurred.  (gs_lev2.ps, zcrd.c)

### Streams

    Fixes bugs:
    	- Filter lookahead caused problems with special files.  (bug
    introduced in 3.70) (stream.h)

### Library

    Fixes bugs:
    	- .getdevparams sometimes returned duplicate entries for /Type.
    (gxiodev.h, gsiodev.c)

Copyright © 2000-2006 Artifex Software, Inc. All rights reserved.

This software is provided AS-IS with no warranty, either express or implied. This software is distributed under license and may not be copied, modified or distributed except as expressly authorized under the terms of that license. Refer to licensing information at http://www.artifex.com/ or contact Artifex Software, Inc., 7 Mt. Lassen Drive - Suite A-134, San Rafael, CA 94903, U.S.A., +1(415)492-9861, for further information.

Ghostscript version 9.18, 5 October 2015