It should adjust the stroke width to integral pixels. Now it does only for vertical and horizontal strokes. Applying fill_adjust over an unadjusted width gives a variable visible width along the line.
Reassigning path and fill problems to Robin Watts.
Reassigning to new email address.
Bug still reproducible in Ghostscript 9.03
Created attachment 20414 [details] Test case The problem still occurs in the current master branch. "true setstrokeadjust" should keep the width of a line constant, i.e. the left and the right side of the line should change at the same position along the line. Ghostscript changes every side independently, creating a variation of thickness of 1 pixel along the line. It appears that Ghostscript does not adjust the width of slanted lines at all.