| Summary: | Inline repainting can be off-by-one with sub-pixel enabled | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Product: | WebKit | Reporter: | Levi Weintraub <leviw> | ||||||
| Component: | Layout and Rendering | Assignee: | Levi Weintraub <leviw> | ||||||
| Status: | RESOLVED FIXED | ||||||||
| Severity: | Normal | CC: | adamk, dglazkov, eae, eric, jamesr, simon.fraser, webkit.review.bot | ||||||
| Priority: | P2 | ||||||||
| Version: | 528+ (Nightly build) | ||||||||
| Hardware: | Unspecified | ||||||||
| OS: | Unspecified | ||||||||
| Attachments: |
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Created attachment 162327 [details]
Patch
Comment on attachment 162327 [details] Patch Attachment 162327 [details] did not pass chromium-ews (chromium-xvfb): Output: http://queues.webkit.org/results/13764581 New failing tests: fast/repaint/repaint-across-writing-mode-boundary.html Comment on attachment 162327 [details]
Patch
LGTM
Committed r128346: <http://trac.webkit.org/changeset/128346> (In reply to comment #2) > (From update of attachment 162327 [details]) > Attachment 162327 [details] did not pass chromium-ews (chromium-xvfb): > Output: http://queues.webkit.org/results/13764581 > > New failing tests: > fast/repaint/repaint-across-writing-mode-boundary.html Just as it did on cr-ews, this is failing on the chromium bots: http://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=fast%2Frepaint%2Frepaint-across-writing-mode-boundary.html Levi, can you take a look? Thanks for the heads up. Fixing now. |
Created attachment 162299 [details] Reproduces the problem. This issue repros easily when repainting selections in a table with sub-pixel offsets, but can likely occur elsewhere. The issue arrises due to repainting being triggered outside of normal paint or layout flow, and thus missing the context from the containing block chain, which leads to differing pixel-snapping. Eventually, I think this should be fixed by preserving the context during layout in something like a FractionalBoxExtent.