changes

这是一个做pdf阅读器的源代码文件,是大家学习阅读器资料的很好参考

Added three missing fclose calls.
Change the default encoding for TrueType fonts (used when the PDF file
  doesn't specify an encoding) from MacRomanEncoding to
  WinAnsiEncoding.
Move X_CFLAGS to the end of the list in CXXFLAGS (in Makefile.in) to
  avoid some of the FreeType2 include path problems.
Fixed an obscure bug in the LZW decoder.  [Thanks to Martin
  Schroeder.]
Fixed a bug in decryption when using the newer (PDF 1.4) algorithm
  with shorter-than-128-bit keys.
Minor optimization for image data streams: the ImageStream class can
  return an entire buffered line.

2.01 (2002-dec-05)
------------------
Redesigned the text extraction process:
  - process the text into "reading order"
  - added a "-layout" flag to pdftotext to switch back to the old
    style, where physical layout is maintained
  - use of the "-raw" flag is no longer recommended
Added the -reload option for xpdf (in remote mode).
Added support for external CID fonts; added the displayCIDFontT1 and
  displayNamedCIDFontT1 commands to the xpdfrc file.
Handle the case of moveto/newpath/clip, which defines an empty
  clipping region (just like moveto/closepath/clip).
Accept XYZ link destinations with missing array elements.
Fix some problems with state save/restore triggered by Type 3 fonts
  that reference other fonts.
Accept bogus font names based on "Symbol": Symbol,{Bold,Italic,
  BoldItalic}.
Fixed color and font resource names in the xpdf man page.
Was using delete instead of gfree in OutlineItem::~OutlineItem.
Set the busy cursor in the find dialog while searching.
Map variants of the copyright, trademark, and registered trademark
  symbols to the proper Unicode codes, not to Adobe's corporate use
  area codes.
Fixed a floating point exception bug in TextOutputDev (check for a
  too-small denominator).
Fixed a typo in TextOutputDev, in the code that generating blank lines
  to add vertical whitespace.
Config files whose last line didn't end with a LF (or CR+LF) weren't
  being handled correctly.
The code that handled CIDToGIDMaps in Type 2 CIDFonts was broken.
Check the per-glyph bounding box in Type 3 fonts, and don't try to
  cache glyphs with bogus bboxes.
Allow ToUnicode CMaps to use fewer than four hex digits in the Unicode
  char indexes.
Added multithreading protection to the GlobalParams class.
Fixed a bug in end-of-stream detection with the TIFF predictor.
Added some characters to MacRomanEncoding to match up with Apple's
  definition.

2.02 (2003-mar-24)
------------------
Rewrote the text extractor code that assembles words into lines to
  better handle vertically overlapping lines.
Add the "match" option for paper size (in PostScript output).
Added support for external 16-bit TrueType fonts; added the
  displayCIDFontTT and displayNamedCIDFontTT commands to the xpdfrc
  file.
Added an Arabic language support package.
Added the Windows-1255 encoding to the Hebrew language package.
A missing NULL check was causing a crash when closing the file in a
  single window (which clears out the window, but leaves it open).
Deal with TrueType fonts whose glyph data is out of order - this
  affected both FreeType rasterization and PostScript generation.
Munge font names in PSOutputDev to avoid names that are problematic
  for ghostscript because they start with an out-of-limits number
  (e.g., 1e999foo).
Modify the TrueType font encoding deciphering algorithm in yet another
  attempt to match up with Acrobat's behavior.
Bounds check the indexHigh value in indexed color spaces.
The text extractor no longer bothers trying to get an average
  character width for Type 3 fonts, since it generally doesn't work
  very well (because Type 3 metrics are unreliable).
Don't crash if the user hits ctrl-G ("find again") before doing a
  find.
Set the button pixmap foreground color correctly.
Handle text drawn backward on 180 degree rotated pages.
Added a magic call to XtUngrabButton after calling XmCreatePopupMenu
  which appears to prevent some very odd problems (idea taken from the
  DDD source code).
Fix the MacOS X fix (needed to include <AvailabilityMacros.h>).
Fixed a bunch of Motif 1.x / X11R5 incompatibilities.  [Thanks to
  William Bader and Albert Chin-A-Young.]
Fixed various bugs in previously untested code in the JBIG2 decoder.
Modify the XPDFCore destructor to avoid a bogus warning message from
  OpenMotif 2.2.
Modified the Type 1C font parser to do proper bounds checking.
Fixed the bounds checking in the TrueType font parser.
Text extractor shouldn't do block merging in physical layout mode.
Fixed a problem in PSOutputDev in level2sep mode with images in a
  Separation color space and with a non-default Decode array.
Text extraction with "-raw" was concatenating lines from the bottom of
  one column and the top of the next.
Handle Type 1C subroutines in the font converters.
Correctly handle progressive JPEG images whose scans are slightly
  different sizes (e.g., the Y scan rounds up to a multiple of 8
  pixels and the Cb/Cr scans round up to 16 pixels).
Avoid a potential divide-by-zero problem in TextOutputDev.
Modified the T1Font and FTFont modules to correctly handle glyphs that
  are larger than the font's claimed bounding box.
Tweak dupMaxDeltaX parameter in TextOutputDev to avoid triggering on
  double characters.
Improved detection in pdfinfo for ISO paper sizes.  [Thanks to Hartmut
  Henkel.]
Xpdf wasn't responding to the TARGETS atom, which prevented pasting
  the selection into various applications.  [Thanks to Phillip Ezolt.]
Handle XObjects with recursive references in their Resources
  dictionaries (in PSOutputDev).
Change PSOutputDev to deal with invalid PDF files that use
  non-embedded TrueType fonts with no encoding.
Check for undersized Widths arrays in fonts.
Add bounds checking code to Array class.
Updated VMS build scripts.  [Thanks to Martin Zinser.]
Tweak the TrueType font handling code (again):
  - char codes in symbolic fonts may or may not be offset by 0xf000
  - discard empty tables because they sometimes confuse FreeType
Fixed bounds checking in the Flate decoder.
Removed a bogus error message for exponential functions without
  explicit C0/C1 values.  [Thanks to Hartmut Henkel.]
Handle the other Unicode cmap type (platform=0) in TrueType fonts.
Added support for the SGI Motif horizontal paned window widget.
  [Thanks to Felix Ritter.]
Ignore extra elements in link destination arrays.
Accept external Type 1 font files with a suffix of ".ps" or no suffix
  at all.
Add a bounds check in the DCT decoder.
Added instructions for building xpdf.exe under cygwin/XFree86.
Tweaked the word separation parameter for raw-mode text extraction.

2.03 (2003-oct-10)
------------------
Rewrote the text extractor to:
  - do a better job with rotated text;
  - handle right-to-left scripts;
  - be faster.
Changed the zoom setting to use a percentage (relative to 72 dpi)
  instead of a zoom "factor".
If the PDF file has an outline, open the outline pane initially.
Added -f and -l options to pdfinfo; print multiple page sizes.
The HAVE_XTAPPSETEXITFLAG test in XPDFApp.cc was backwards.
The BitsPerComponent entry is optional in image mask objects.
Render any annotation with an appearance stream, instead of just
  Widget and Stamp annotations.
Fix a bug in the TrueType font checker: the test for an unsorted
  'loca' table was wrong.
Modify the TrueType cmap selection algorithm yet again to try to match
  Adobe's behavior.
Changed sqrt(2) to sqrt(2.0) in pdfinfo.cc to make various compilers
  happy.
Fixed a deadlock problem (when MULTITHREADING is set); cleaned up some
  other problems with the locking code.
Fixed a bug in the interpolation code for type 0 (sampled) functions.
Implemented type 1 (function-based) shaded fills.
Fixed some stupid bugs in the JBIG2 decoder (introduced with the
  previous optimization work).
Fixed a typo in the code that parses vertical font metrics for CID
  fonts that was causing a seg fault.
Fixed a couple of bugs that were causing seg faults with badly damaged
  PDF files.
Limit the number of nested Forms to avoid infinite recursion (in buggy
  PDF files).
Add a special case for rectangular clip regions - make sure these
  don't drop pixels on the right and bottom edges.
Tell FreeType not to use glyph bitmaps when in anti-aliased mode.
Read all of the border style info for links.
All of the shaded fill types now do at least one bisection to avoid
  problems when the colors at the endpoints of the domain are the
  same.
If the Length2 parameter for an embedded Type 1 font was incorrect
  (too small), pdftops was losing font data.
Deal with (broken) DCT streams that use the same component ID number
  for different components.
The MediaBox page attribute was not being inherited correctly.
Fixed a bug in the Type 1C font converter related to local
  subroutines.
The Type 1C -> Type 1 font converter was allocating the font dictionary
  one slot too small.
Added a missing private dictionary entry to Type 1 fonts generated by
  the Type 1C converter.  [Thanks to Michael Shell.]
Fixed bugs in the tiling pattern fill code.
Try the TrueType 0xf000 char code offset hack for the MacRoman
  encoding too (in addition to MS Symbol).
Update the font metrics info for the Base 14 fonts to include the Euro
  character.
SECURITY HOLE: Escape various characters in URLs before running a web
  browser (or movie viewer).  [Fixed in 2.02p11]
SECURITY HOLE: In the dialog used to verify "launch" links, provide a
  scrolling view if the command to be run is excessively long.  [Fixed
  in 2.02p11]
Added an option to disable insertion of page breaks (form feed
  characters) in extracted text (pdftotext -nopgbrk; xpdfrc
  "textPageBreaks" option).
Check for 8-bit fonts that specify an out-of-range FirstChar or
  LastChar.
Correctly handle an obsolete Type 2 charstring op (in the Type
  1C-to-Type 1 font converter).  [Thanks to Helge Blischke.]
Use the font encoding info to fill in holes in the ToUnicode map.
Added character names for Bulgarian (in the Cyrillic support pacakage)
  and Greek.
Handle clipping to text in xpdf and pdftops.
Fix color space detection in DCT decoder.  [Thanks to Dwight Kelly.]
Added the "unicodeToUnicode" xpdfrc option, intended (initially) for
  Arabic support.
Handle the case in PSOutputDev where two font objects refer to the
  same embedded TrueType font, but with different encodings.  [Thanks
  to Frank Siegert.]
Kill any pre-existing path before drawing a form (or annotation).
Save state before rendering page content; restore state afterward.
Fix Stream::reset/close to work correctly with encoder streams; fix
  PSOutputDev to use Stream::close consistently.
Fix a seg fault when hitting the 'back' button after closing a file.
GfxState::getStrokeGray was returning the fill gray value (this only
  affected Level 1 PS output).
Change PSOutputDev to reuse dictionaries in Level 1 mode (since Level
  1 PS interpreters don't do garbage collection).  [Thanks to Frank
  Siegert.]
PSOutputDev was generating incorrect translations for landscape-mode
  pages.
Implemented shading pattern color spaces.
PSOutputDev wasn't correctly handling Type 3 fonts which used image
  resources (as opposed to inline images).  [Thanks to Frank Siegert.]
The fix from 1.00 which clipped out-of-bounds points was a bit too
  aggressive.
Do proper Floyd-Steinberg dithering in XOutputDev.
Don't automatically check for a null owner password (to match Adobe's
  behavior).
Allow the FlateDecode filter in Level 3 PostScript output.
Fixed small bugs in the Type 1C -> Type 1 converter and Type 1C ->
  Type 0 converter.  [Thanks to Tom Kacvinsky.]
Work around another weird Motif problem with the right button menu
  (which was sometimes causing the menu to not be displayed).
Make the code that handles fonts defined directly in the resource dict
  more robust.
Add a brief description of the outline pane to the xpdf man page.
Ignore extra operands to content stream operators.
Fixed a bug in the CCITTFax decoder.
Allow the Count entry in a Pages dictionary to be a real number
  (because some PDF generators actually do this).
Shading pattern fills weren't being clipped correctly.
Incorrect shallow copies in GfxRadialShading and StitchingFunction.
The StitchingFunction destructor wasn't checking for funcs being
  NULL.
Change the TrueType code-to-GID mapping code so it looks at the
  TrueType 'post' table.
Set the print command in the print dialog once at startup, don't
  change it each time a file is (re)loaded.
Generate the %%BoundingBox comment in regular PostScript files (not
  just EPS files).
Fixed a bug in the Unicode CMap parser.

3.00 (2004-jan-22)
------------------
New PDF rasterizer ("Splash").
Added support for PDF 1.5:
  - JPX (JPEG 2000) decoder
  - XRef streams
  - object streams
  - DeviceN color spaces with up to 32 components
  - Added new CMaps to the CJK language support packages
Replaced pdftopbm with pdftoppm (which can generate PBM, PGM, and PPM
  files).
Reorganized the font file parser code into a new library ("Fofi").
Removed support for FreeType 1.x.
Removed support for X server fonts - Xpdf (and pdftoppm) will now
  search for the URW fonts (from ghostscript).
Changed the "-t1lib" and "-freetype" switches; replaced the
  "t1libControl" and "freetypeControl" config file options with
  "enableT1lib", "enableFreeType", and "antialias".
Added the "-box" option to pdfinfo.
Added imageable area support to PSOutputDev (for CUPS); added the
  "psImageableArea" config file option.
Added the "-nocrop", "-expand", "-noshrink", and "-noc