imported/w3c/css/css-multicol-1/multicol-rule-dashed-000.xht has been failing on the GTK port since I added expectations for it in r194854. There is a small pixel difference which the test claims should not be there (should be "IDENTICAL" says the test). This is very strange, since I got those expectations straight from the test bot. This sort of implies the test broke between when I got the expected results from the bot and when I uploaded them, which is improbable. I don't know how else to explain what happened. Since it's only a small pixel diff (the thin blue bars are missing), perhaps we can just make this the new expectation.
imported/w3c/css/css-multicol-1/multicol-zero-height-001.xht is completely broken.