Bug 692245

Summary:	Warning: Pattern stream has unbalanced q/Q operators (too many q's)
Product:	Ghostscript	Reporter:	Marcos H. Woehrmann <marcos.woehrmann>
Component:	PDF Interpreter	Assignee:	Alex Cherepanov <alex>
Status:	NOTIFIED FIXED
Severity:	normal	CC:	robin.watts
Priority:	P2
Version:	master
Hardware:	PC
OS:	All
Customer:	700	Word Size:	---

Description Marcos H. Woehrmann 2011-05-31 09:06:46 UTC

The customer reports and I've verified that Ghostscript reports the warning "Warning: Pattern stream has unbalanced q/Q operators (too many q's)" before generating a "/typcheck in --run--" error.  This occurs with all versions of Ghostscript I tested, including head (d0055ac144c1f1a51e906976b85e8e2119b5a2db).  

The command line I'm using for testing:

  bin/gs -sDEVICE=ppmraw -o test.ppm ./Canton_Landscape_bed_layout.pdf


Acrobat 10 and Apple Preview read the file without difficulty, mupdf produces the message:

Assertion failed: (contrib_cols == NULL || contrib_cols->count == dst_w_int), function fz_scale_pixmap, file draw/draw_scale.c, line 1091.

Comment 2 Alex Cherepanov 2011-05-31 13:29:43 UTC

The file has a rather long number:

36.00000 0.00000 0.00000 36.00000 0.0000 -43583108498802323000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.0000 cm

If this number is replaced with an ordinary one, the file runs to completion.

Comment 3 Robin Watts 2011-05-31 14:57:37 UTC

The same line causes the problem in mupdf - the scale function is entered with an invalid matrix. A fix for this has been developed and is working it's way into the mupdf repo now.

Comment 4 Alex Cherepanov 2011-06-01 04:35:43 UTC

Make pattern handling code tolerant to pattern streams that leave
some junk on the operand stack. For instance, this can happen when
processing of a stream terminates prematurely.

http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=db4af9eaf902dbac931ca8c88c586df9d160fb72