Bug 87137 – Layout Test fast/block/margin-collapse/103.html is failing (layout assertion)

• Status: RESOLVED
• Resolution: WORKSFORME
• Component: Tools / Tests

[Joshua Bell]

The following layout test is failing on [insert platform]

fast/block/margin-collapse/103.html

Probable cause:

WebKit blame range: http://trac.webkit.org/log/?verbose=on&rev=117821&stop_rev=117815

Abbreviated stack is:

STDERR: ASSERTION FAILED: newLogicalTop >= logicalTop
STDERR: Backtrace:
STDERR: 	WebKit::WebURLRequest::hasUserGesture [0x0247F0EE+11353182]
...
STDERR: 	WebKit::WebURLRequest::hasUserGesture [0x02EBCBB6+22091558]
STDERR: 	webkit_glue::WebURLResponseExtraDataImpl::~WebURLResponseExtraDataImpl [0x099788AE+949584]
STDERR: 	(No symbol) [0x005071B9]
...
STDERR: 	(No symbol) [0x0050DFFC]
STDERR: 	base::SharedMemory::CreateAnonymous [0x00B67B7F+364615]
...
STDERR: 	base::SharedMemory::CreateAnonymous [0x00B6EC70+393528]
STDERR: 	(No symbol) [0x004ABB8D]
...
STDERR: 	(No symbol) [0x00500A0F]
STDERR: 	RegisterWaitForInputIdle [0x7C817077+73]
Test results:

http://build.chromium.org/f/chromium/layout_test_results/Webkit_Win__dbg__1_/138145/layout-test-results.zip

[Joshua Bell]

Subpixel layout is the most likely culprit given the range and assert. Assigning to eae@ for investigation.

[Joshua Bell]

Also, only failing on webkit win debug.

[Joshua Bell]

Flakiness dashboard link:

http://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=fast%2Fblock%2Fmargin-collapse%2F103.html

[Emil A Eklund]

Created attachment 143420 [details]
Reduced test case

The crash seems to be window size specific. With the reduced test case (attached) it doesn't crash when loaded but as soon as the window is made small enough to toggle scrolling

[Joshua Bell]

No longer showing on flakiness dashboard. Presumably fixed, re-open at will.