Consider a path that happens to be dashed in such a way that the end of one on section exactly corresponds with a corner in the path. Postscript (at least Acrobat and Ghostscripts implementation of it) appears to join this line segment around the corner to the empty 'dash' section. This can produce odd looking caps. XPS (at least xps2tiff, which calls microsofts own code for rendering) does not join in this way. Other xps graphics renderers differ in their operation here (Software Imaging's XPS viewer for example gives a different result to both ghostscript and xps2tiff). Supporting both different ways of working within one graphics library will require a switch of some kind, I think. I have a #define locally that seems to work (needs more testing), but this isn't a runtime solution.
Created attachment 5737 [details] dash.xps This xps file, created by Tor/Myself to demonstrate dashing/capping behaviour shows the problem. Look at the lower right hand corner of the green path.
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