Comment 17 for bug 318130

Created attachment 57654
align fills

Here's an experimental patch for the cairo backend. It doesn't completely solve the problem but it does eliminate the seams in some cases.

Some test cases I tried it with:
https://bugs.launchpad.net/ubuntu/+source/poppler/+bug/348679/+attachment/510918/+files/test.pdf
Eliminates the seams sometimes depending on the resolution rendered at.

https://bugs.launchpad.net/ubuntu/+source/poppler/+bug/318130/+attachment/441616/+files/seminar1.pdf
Seems to eliminate the seams at all resolutions I tested.

https://bugs.launchpad.net/ubuntu/+source/poppler/+bug/387016/+attachment/606341/+files/Evince%20incorrect%20rendering.zip
Eliminates the seams for all resolutions I tested except 150ppi where the one seam is worse. This is because the the coordinates of the adjacent fill where the line is worse are not identical (0.1 difference vertically).