"xref subsection syntax error at 1058495", "pngout failed, status=0x200" [patches]

[GoogleCodeExporter]

The attached patches fix two issues with a file created by "Microsoft
Office Word 2007"

If an xref started "0 0\ntrailer", pdfsizeopt would raise an exception
around line 3096 instead of continuing to the real xref.

$ python pdfsizeopt.py ColumnSelections.pdf
info: loading PDF from: ColumnSelections.pdf
info: loaded PDF of 1058676 bytes
warning: problem with xref table, finding objs anyway: xref subsection
syntax error at 1058495
Traceback (most recent call last):
  File "pdfsizeopt.py", line 6158, in <module>
    main(sys.argv)
  File "pdfsizeopt.py", line 6134, in main
    ).Load(file_name)
  File "pdfsizeopt.py", line 2997, in Load
    data, do_ignore_generation_numbers=self.do_ignore_generation_numbers)
  File "pdfsizeopt.py", line 3199, in ParseWithoutXref
    assert prev_obj_num not in obj_starts, 'duplicate obj %d' % prev_obj_num
TypeError: int argument required

@@ -3092,6 +3092,12 @@
         # For testing whitespace before trailer: enc.pdf
         match = re.match(
             r'(\d+)\s+([1-9]\d*)\s+|[\0\t\n\r\f ]*(xref|trailer)\s',
xref_head)
+        old_object = False
+        if not match:
+          # skip over old objects
+          old_object = re.match(
+              r'(\d+)\s+(0)\s+|[\0\t\n\r\f ]*(xref|trailer)\s', xref_head)
+          match = old_object
         if not match:
           raise PdfXrefError('xref subsection syntax error at %d' % xref_ofs)
         if match.group(3) is not None:
@@ -3122,7 +3128,7 @@
                 obj_ofs = 0
               else:
                 raise PdfXrefError('duplicate obj %s' % obj_num)
-            if obj_ofs != 0:
+            if (obj_ofs != 0) and (not old_object):
               # for testing: obj 10 in pdfsizeopt_charts.pdf has offset 0:
               # "0000000000 00000 n \n"
               if obj_ofs in obj_starts_rev:

pngout returns 2 instead of 0 if it can not compress the file.  This is
just a warning, and pdfsizeopt can still continue.

$ python pdfsizeopt.py ColumnSelections.pdf
...
info: executing image optimizer jbig2: jbig2 -p pso.conv-16.sam2p-pr.png
>pso.conv-16.jbig2
info: executing image optimizer pngout: pngout pso.conv-16.parse.png
pso.conv-16.pngout.png 
 In:      87 bytes               pso.conv-16.parse.png /c3 /f0 /d1
Out:      91 bytes               pso.conv-16.pngout.png /c3 /f0 /d1, 1 colors
Unable to compress further: copying original file
info: pngout failed, status=0x200
Traceback (most recent call last):
  File "pdfsizeopt.py", line 6167, in <module>
    main(sys.argv)
  File "pdfsizeopt.py", line 6153, in main
    pdf.OptimizeImages(use_pngout=use_pngout, use_jbig2=use_jbig2)
  File "pdfsizeopt.py", line 5082, in OptimizeImages
    cmd_name='pngout'))
  File "pdfsizeopt.py", line 4551, in ConvertImage
    assert 0, '%s failed (status)' % cmd_name
AssertionError: pngout failed (status)

@@ -4536,7 +4543,10 @@
     print >>sys.stderr, ('info: executing image optimizer %s: %s' %
         (cmd_name, cmd))
     status = os.system(cmd)
-    if status:
+    if status == 0x200:
+      # pngout returns 2 if it can not compress the file further, but this
is not an error
+      print >>sys.stderr, 'info: %s returned, status=0x%x, continuing' %
(cmd_name, status)
+    elif status:
       print >>sys.stderr, 'info: %s failed, status=0x%x' % (cmd_name, status)
       assert 0, '%s failed (status)' % cmd_name
     assert os.path.exists(targetfn), (

William
williambader@hotmail.com

Original issue reported on code.google.com by william.bader@gmail.com on 27 Mar 2010 at 4:32

Attachments:

• pdfsizeopt.pat

[GoogleCodeExporter]

Sample PDF that shows the problems (for testing only, do not copy or repost
unnecessarily)

Original comment by william.bader@gmail.com on 28 Mar 2010 at 4:29

Attachments:

• ColumnSelections.pdf

[GoogleCodeExporter]

Thank you for reporting these bugs. I can't reproduce the first one in r151 
(pdfsizeopt parses the attached PDF without warnings or errors), and I've fixed 
the pngout return status bug in r152.

Original comment by pts...@gmail.com on 11 Feb 2011 at 12:55

• Changed state: Fixed