Created attachment 5142 [details]
test.pdf

See this pdf file, please compare the output of both

       gs -sDEVICE=x11
       gs -sDEVICE=x11alpha

as you can see the bitmaps for the signatures are not
shown with x11alpha.

Created attachment 5143 [details]
ghostscript-8.64-pdf.dif

This patch I use currently for a workaround the problems seen
with this and some other pdf files.

Created attachment 5199 [details]
ghostscript-8.64-pdf.dif

During debugging for bug #690575 I found out that two parts are not required
with ghostscript 8.64 (gdevpdfo.c and gdevpdfr.c) but solve the extrem slowdown

of the pfdwrite device.  These two changes I had introduced to avoid crashes of

ghostscript 8.62 with the PostScript files
http://sips.inesc-id.pt/~pfzt/gs_bug_fig.eps and
http://sips.inesc-id.pt/~pfzt/gs_bug_fig2.eps
without noticing the side effect.

Hmm, can I just check what you are saying ? 

If you don't apply the two changes to the pdfwrite sources in the first diff
here, then the slowdown you see in issue #690575 does not occur ? That would
explain why I don't see that problem of course.

You are then also saying that you introduced those changes to fix a problem with
8.62 and with the 8.64 code these pdfwrite changes are not required at all ?

Yes exactly this is what I've said ... gs 8.62 had run onto a NULL
pointer without these two changes (compare with the report found at
http://bugzilla.novell.com/show_bug.cgi?id=409605) and now gs 8.64
does not.

Created attachment 5203 [details]
bug-152780_support-graf.pdf

Yet an other pdf file which cause trouble with ghostscript.
It is visible with  `gs -sDEVICE=x11' but cause a fatal error
if `gs -sDEVICE=x11alpha' is used:

  > gs -sDEVICE=x11alpha bug-152780_support-graf.pdf
  GPL Ghostscript 8.64 (2009-02-03)
  Copyright (C) 2009 Artifex Software, Inc.  All rights reserved.
  This software comes with NO WARRANTY: see the file COPYING for details.
  Processing pages 1 through 1.
  Page 1
  Error: /unknownerror in --run--
  Operand stack:
     --nostringval--   --dict:6/15(L)--   0.0	596.0
  Execution stack:
  %interp_exit	 .runexec2   --nostringval--   --nostringval--	
--nostringval--   2   %stopped_push   --nostringval--	--nostringval--  
--nostringval--   false   1   %stopped_push   1878   1	 3   %oparray_pop  
1877   1   3   %oparray_pop   1861   1	 3   %oparray_pop   --nostringval--  
--nostringval--   2   1   1   --nostringval--	%for_pos_int_continue  
--nostringval--   --nostringval--   false   1	%stopped_push	--nostringval--
  --nostringval--   --nostringval--   %array_continue	--nostringval--   false
  1   %stopped_push   --nostringval--	%loop_continue	 --nostringval--
  Dictionary stack:
  --dict:1166/3371(ro)(G)--   --dict:1/20(G)--	 --dict:74/200(L)--  
--dict:74/200(L)--   --dict:106/127(ro)(G)--   --dict:278/300(ro)(G)--	
--dict:22/25(L)--   --dict:4/6(L)--   --dict:21/40(L)--   --dict:3/5(L)--
  Current allocation mode is local
  Last OS error: 11
  GPL Ghostscript 8.64: Unrecoverable error, exit code 1

... for this I've no patch around.

removing the bbox_create_compositor line
(http://bugs.ghostscript.com/show_bug.cgi?id=689340#c6) fixes the crash with
attachment 5203 [details].

removing the compositor line also make attachment 5142 [details] display correctly, so it
is a simplier "fix" than 5199, as far as 'fix' goes.

This appears to be fixed with rev 12380