Bug 128310 – AX: Crash in WebCore::AXObjectCache::computedObjectAttributeCache

• Status: RESOLVED
• Resolution: FIXED
• Component: Accessibility

[chris fleizach]

From comments in
  https://bugs.webkit.org/show_bug.cgi?id=127439


#0  0x00007ffff052c95a in std::unique_ptr<WebCore::AXComputedObjectAttributeCache, std::default_delete<WebCore::AXComputedObjectAttributeCache> >::get (this=0xd0) at /usr/include/c++/4.7/bits/unique_ptr.h:223
#1  0x00007ffff055b056 in WebCore::AXObjectCache::computedObjectAttributeCache (this=0x0) at /home/michal/source/WebKit/Source/WebCore/accessibility/AXObjectCache.h:211
#2  0x00007ffff0559b22 in WebCore::AccessibilityObject::accessibilityIsIgnored (this=0x776e80) at /home/michal/source/WebKit/Source/WebCore/accessibility/AccessibilityObject.cpp:2105
#3  0x00007ffff0559820 in WebCore::AccessibilityObject::notifyIfIgnoredValueChanged (this=0x776e80) at /home/michal/source/WebKit/Source/WebCore/accessibility/AccessibilityObject.cpp:2018
#4  0x00007ffff052a3f4 in WebCore::AXObjectCache::recomputeIsIgnored (this=0x813b20, renderer=0x82ebb0) at /home/michal/source/WebKit/Source/WebCore/accessibility/AXObjectCache.cpp:905
#5  0x00007ffff0fab3da in WebCore::RenderBlock::deleteLines (this=0x82ebb0) at /home/michal/source/WebKit/Source/WebCore/rendering/RenderBlock.cpp:920
#6  0x00007ffff0fe2795 in WebCore::RenderBlockFlow::deleteLines (this=0x82ebb0) at /home/michal/source/WebKit/Source/WebCore/rendering/RenderBlockFlow.cpp:1906
#7  0x00007ffff0fabce6 in WebCore::RenderBlock::collapseAnonymousBoxChild (parent=0xa1cba0, child=0x82ebb0) at /home/michal/source/WebKit/Source/WebCore/rendering/RenderBlock.cpp:1084
#8  0x00007ffff0fac171 in WebCore::RenderBlock::removeChild (this=0xa1cba0, oldChild=...) at /home/michal/source/WebKit/Source/WebCore/rendering/RenderBlock.cpp:1160

[Radar WebKit Bug Importer]

<rdar://problem/16002078>

[chris fleizach]

In frame 1, the cache has become null, which means asking axObjectCache() in frame 3 either found no document, or no axObjectCache at that document, which can happen when the render tree is no longer living

we need to be more careful about using the axObjectCache() in ax code

[Radar WebKit Bug Importer]

<rdar://problem/16002095>

[chris fleizach]

Created attachment 223342 [details]
patch

[Alexey Proskuryakov]

Comment on attachment 223342 [details]
patch 

r=me

Please wait for EWS testers to become green.

[WebKit Commit Bot]

Comment on attachment 223342 [details]
patch 

Clearing flags on attachment: 223342

Committed r163586: <http://trac.webkit.org/changeset/163586>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.