(I am guessing it is a pxlcolor/pxlmono bug, rather than a ghostpdl bug - feel free to change later). attachment 4392 [details] (bug 690069), aftering addressing the rotation and the color space issue, result in a pxl stream that's still showing some visual artifects under ghostpdl. Will attach the pxl stream. I have checked the problem is not a result of those two bug fixes. (i.e. unpatched svn heads also shows those visual effects, plus large PXL files).
Created attachment 5504 [details] pxl stream from ps attachment 4392 [details] PXL derived from attachement 4392 with pxlmono. View page two with ghostpdl and compared with original. Texts probably have transparent background rendered, opague I think, as a first guess. (either the pxl generator or the viewer is buggy, don't know which yet). pxlcolor also shows similar problem.
Comment on attachment 5504 [details] pxl stream from ps attachment 4392 [details] derived from private data, marked also private.
The HP Color Laserjet 4600 renders the pxl stream the same as ghostpdl, so this is a pxlmono/pxlcolor device bug.
The issue is probably in the same code area as bug 688372 .
Created attachment 5642 [details] patch that make this renders correctly. This file is a curious case - it is black + mask. Setting the mask to white and the logical operation to S & D should be the same as S + transparent white. But somehow only S & D works, so there is what the patch does.
Setting S + transparent results in transparent text over white background, instead of the intended black over transparent background. Just a curiosity,
The patch above was eventually integrated and included with other changes in the same area of code as the black-on-mask code in part of r10305.