Bug 5699

Summary: REGRESSION: incomplete repaint
Product: WebKit Reporter: mitz
Component: Layout and RenderingAssignee: Dave Hyatt <hyatt>
Status: VERIFIED FIXED    
Severity: Normal CC: webkit-bugs
Priority: P1    
Version: 420+   
Hardware: Mac   
OS: OS X 10.4   
Attachments:
Description Flags
Testcase
none
Possible fix
hyatt: review+
Complete patch w/ChangeLog entry and manual test none

mitz
Reported 2005-11-10 07:23:09 PST
Repaint following layout changes is incomplete. To reproduce: open the testcase. Click "Test!". A copy of "Lorem ipsum" is left behind as it moves down. Selecting all text or otherwise triggering repaint of that area clears it.
Attachments
Testcase (299 bytes, text/html)
2005-11-10 07:24 PST, mitz 		no flags
Details
Possible fix (795 bytes, patch)
2005-12-25 11:36 PST, mitz 		hyatt: review+
DetailsFormatted DiffDiff
Complete patch w/ChangeLog entry and manual test (2.76 KB, patch)
2005-12-26 10:14 PST, mitz 		no flags
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
mitz
Comment 1 2005-11-10 07:24:37 PST
Created attachment 4658 [details] Testcase
mitz
Comment 2 2005-12-25 11:36:26 PST
Created attachment 5279 [details] Possible fix
mitz
Comment 3 2005-12-25 11:37:50 PST
Comment on attachment 5279 [details] Possible fix RenderObject::repaintAfterLayoutIfNeeded was lying about whether it did a full repaint. This patch makes it return the truth. The return value is only used in RenderBlock::layoutBlock. An alternative approach (perhaps better performance-wise) is to let repaintAfterLayoutIfNeeded take an extra "must repaint" rect as an argument and assure that it was repainted as well (if it returned true). If/when the code change is approved, I'll submit a more commit-friendly patch. I don't think there can be an automatic test for such a rendering bug.
Maciej Stachowiak
Comment 4 2005-12-25 16:40:29 PST
I think a pixel test could catch this. You'd have to defer dumping, and programmatically do the equivalent of the button click from a timer or something. Would that work?
Dave Hyatt
Comment 5 2005-12-25 22:42:55 PST
Comment on attachment 5279 [details] Possible fix Nice one. I do not feel bad missing this one at all heh.
mitz
Comment 6 2005-12-26 10:14:41 PST
Created attachment 5283 [details] Complete patch w/ChangeLog entry and manual test
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