Bug 24143 – Crash occurs at WebCore::AccessibilityTable::isTableExposableThroughAccessibility() when applying a link in GMail

• Component: Accessibility
• Status: RESOLVED FIXED

[chris fleizach]

Thread 0 Crashed:
0   com.apple.WebCore             	0x00007fff83ef3915 WebCore::AccessibilityTable::isTableExposableThroughAccessibility() + 773
1   com.apple.WebCore             	0x00007fff83ef3c3b WebCore::AccessibilityTable::AccessibilityTable(WebCore::RenderObject*) + 91
2   com.apple.WebCore             	0x00007fff83c7cc12 WebCore::AccessibilityTable::create(WebCore::RenderObject*) + 50
3   com.apple.WebCore             	0x00007fff83bd40eb WebCore::AXObjectCache::get(WebCore::RenderObject*) + 363
4   com.apple.WebCore             	0x00007fff83bdf0ed WebCore::AccessibilityRenderObject::childrenChanged() + 61
5   com.apple.WebCore             	0x00007fff83bd8c05 WebCore::AXObjectCache::childrenChanged(WebCore::RenderObject*) + 101
6   com.apple.WebCore             	0x00007fff83a8febe WebCore::RenderObject::destroy() + 222
7   com.apple.WebCore             	0x00007fff83a8fce7 WebCore::RenderBox::destroy() + 71
8   com.apple.WebCore             	0x00007fff8411570d WebCore::RenderObjectChildList::destroyLeftoverChildren() + 141
9   com.apple.WebCore             	0x00007fff840f7476 WebCore::RenderBlock::destroy() + 54
10  com.apple.WebCore             	0x00007fff83a8fc46 WebCore::Node::detach() + 38
11  com.apple.WebCore             	0x00007fff83a8fafe WebCore::Element::detach() + 110
12  com.apple.WebCore             	0x00007fff83b4cc01 WebCore::HTMLInputElement::detach() + 17
13  com.apple.WebCore             	0x00007fff83a8fa6c WebCore::ContainerNode::detach() + 44
14  com.apple.WebCore             	0x00007fff83a8fafe WebCore::Element::detach() + 110
15  com.apple.WebCore             	0x00007fff83a8fa6c WebCore::ContainerNode::detach() + 44
16  com.apple.WebCore             	0x00007fff83a8fafe WebCore::Element::detach() + 110
17  com.apple.WebCore             	0x00007fff83a8fa6c WebCore::ContainerNode::detach() + 44
18  com.apple.WebCore             	0x00007fff83a8fafe WebCore::Element::detach() + 110
19  com.apple.WebCore             	0x00007fff83a8fa6c WebCore::ContainerNode::detach() + 44
20  com.apple.WebCore             	0x00007fff83a8fafe WebCore::Element::detach() + 110
21  com.apple.WebCore             	0x00007fff83a8fa6c WebCore::ContainerNode::detach() + 44
22  com.apple.WebCore             	0x00007fff83a8fafe WebCore::Element::detach() + 110
23  com.apple.WebCore             	0x00007fff83a8fa6c WebCore::ContainerNode::detach() + 44
24  com.apple.WebCore             	0x00007fff83a8fafe WebCore::Element::detach() + 110
25  com.apple.WebCore             	0x00007fff83a8fa6c WebCore::ContainerNode::detach() + 44
26  com.apple.WebCore             	0x00007fff83a8fafe WebCore::Element::detach() + 110
27  com.apple.WebCore             	0x00007fff83a8fa6c WebCore::ContainerNode::detach() + 44
28  com.apple.WebCore             	0x00007fff83a8fafe WebCore::Element::detach() + 110
29  com.apple.WebCore             	0x00007fff83a8fa6c WebCore::ContainerNode::detach() + 44
30  com.apple.WebCore             	0x00007fff83a8fafe WebCore::Element::detach() + 110
31  com.apple.WebCore             	0x00007fff83a8fa6c WebCore::ContainerNode::detach() + 44
32  com.apple.WebCore             	0x00007fff83a8fafe WebCore::Element::detach() + 110
33  com.apple.WebCore             	0x00007fff83b323f5 WebCore::ContainerNode::removeChild(WebCore::Node*, int&) + 405
34  com.apple.WebCore             	0x00007fff83b4f3c7 WebCore::JSNode::removeChild(JSC::ExecState*, JSC::ArgList const&) + 87
35  com.apple.WebCore             	0x00007fff83b4f36e WebCore::jsNodePrototypeFunctionRemoveChild(JSC::ExecState*, JSC::JSObject*, JSC::JSValuePtr, JSC::ArgList const&) + 110
36  com.apple.JavaScriptCore      	0x00007fff876540b9 JSC::Interpreter::cti_op_call_NotJSFunction(void**) + 537
37  ???                           	0x000000011b4d62ba 0 + 4753023674
38  com.apple.JavaScriptCore      	0x00007fff8760805e JSC::Interpreter::execute(JSC::FunctionBodyNode*, JSC::ExecState*, JSC::JSFunction*, JSC::JSObject*, JSC::ArgList const&, JSC::ScopeChainNode*, JSC::JSValuePtr*) + 558
39  ???

[chris fleizach]

Created attachment 27949 [details]
patch to fix crash

[chris fleizach]

Created attachment 27951 [details]
patch to fix crash

[chris fleizach]

Created attachment 27952 [details]
patch to fix crash

[chris fleizach]

Created attachment 27954 [details]
patch to fix crash

[Beth Dakin]

Comment on attachment 27954 [details]
patch to fix crash

Hey Chris! This patch looks good. My only comments really have to go with naming conventions. I am not wild about the names get() and getIfExists(). How about one of the following:

get() = getOrCreate()
getIfExists() = get()

or

get() = add()
getIfExists() = get()

The add() one is a little weird, I know, but that is a common naming convention for this kind of thing is some other parts of WebCore…basically it means add this to the cache or just return it if it already exists. That being said, I like getOrCreate() as well, so you can choose whichever you prefer.

[chris fleizach]

I will go with getOrCreate. that is a little more explicit than "add", since most of the time this method is used, it is just to get things. changing get to getOrCreate will make this a much bigger patch 

(In reply to comment #5)
> (From update of attachment 27954 [details] [review])
> Hey Chris! This patch looks good. My only comments really have to go with
> naming conventions. I am not wild about the names get() and getIfExists(). How
> about one of the following:
> 
> get() = getOrCreate()
> getIfExists() = get()
> 
> or
> 
> get() = add()
> getIfExists() = get()
> 
> The add() one is a little weird, I know, but that is a common naming convention
> for this kind of thing is some other parts of WebCore…basically it means add
> this to the cache or just return it if it already exists. That being said, I
> like getOrCreate() as well, so you can choose whichever you prefer.
> 

[chris fleizach]

http://trac.webkit.org/changeset/41236

[chris fleizach]

*** Bug 22340 has been marked as a duplicate of this bug. ***