I finally got around to using the new images-as-patterns feature. Unsurprisingly, Inkscape is subject to the same problem as most renderers -- due to roundoff error, opposite edges of the tile pattern will "peek around". That is almost impossible to avoid when dealing with an exactly-fitted tiled pattern.

See the attached image for a visual demonstration of this. I have imported the same image twice; once as a pattern (left), and once as a straight image (right). Note that there is no stroke on the former.

Unless we can find a workaround for this that will work in all SVG renderers (i.e. we can't just add a hack to our renderer to account for this case), we CANNOT import images as patterns (certainly not by default).

One possible workaround would be to add an amount of empty "padding" around the image in the pattern. That does have its own disadvantages, however:

* the tiling behavior is sometimes desirable (once users have the ability to manipulate pattern transforms)

* the same roundoff errors could produce gaps between the image in the patterned fill and the stroke (if any)

Any other ideas?

-mental