Bug 103424
| Summary: | [Qt] A new compositing bug uncovered by r135859 | ||
|---|---|---|---|
| Product: | WebKit | Reporter: | Csaba Osztrogonác <ossy> |
| Component: | New Bugs | Assignee: | Nobody <webkit-unassigned> |
| Status: | RESOLVED INVALID | ||
| Severity: | Normal | CC: | allan.jensen, hausmann, junov, ossy, simon.fraser |
| Priority: | P2 | ||
| Version: | 420+ | ||
| Hardware: | All | ||
| OS: | All | ||
| Bug Depends on: | |||
| Bug Blocks: | 87008, 103275 | ||
Csaba Osztrogonác
fast/backgrounds/background-opaque-images-over-color.html started to
fail on Qt after r135859 and r135861 - refactoring to reftest
See https://bugs.webkit.org/show_bug.cgi?id=103275 for details.
Image diff on the Qt bot: http://build.webkit.sed.hu/results/x86-64%20Linux%20Qt%20Release/r135862%20%2845465%29/fast/backgrounds/background-opaque-images-over-color-diffs.html
| Attachments | ||
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| Add attachment proposed patch, testcase, etc. |
Csaba Osztrogonác
I skipped it by r135865. Please unskip it with the proper fix.
Allan Sandfeld Jensen
It seems to be case 3 and case 8 that that fails.
<div id="case_3" class="redBack" style="background-image: -webkit-cross-fade(url(../../http/tests/multipart/resources/green-100x100.png), url(../../http/tests/multipart/resources/green-100x100.png), 50%)"></div>
<div id="case_9" class="redBack" style="background-repeat: no-repeat; background-image: url(../../http/tests/multipart/resources/green-100x100.png),url(resources/64x32-red.png)"></div>
So it appears cross-fading between two identical images produces something that is not an identical image.
Allan Sandfeld Jensen
A quick investigation shows that cross-fading images is crossplatform code. It does however rely on a PLUS composition to ensure the two images opacity adds up to 100%. It could appear that QPainter does not composition opacity values set by QPainter::setOpacity but only thoses in the alpha values of painted images.
Jocelyn Turcotte
=== Bulk closing of Qt bugs ===
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If you believe that this is still an important QtWebKit bug, please fill a new report at https://bugreports.qt-project.org and add a link to this issue. See http://qt-project.org/wiki/ReportingBugsInQt for additional guidelines.