Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: 87adaeb6e0784bbc78fb88e5db1178d06957243f
https://github.com/WebKit/WebKit/commit/87adaeb6e0784bbc78fb88e5db1178d06957243f
Author: Tyler Wilcock <[email protected]>
Date: 2023-02-18 (Sat, 18 Feb 2023)
Changed paths:
A LayoutTests/accessibility/empty-text-under-element-cached-expected.txt
A LayoutTests/accessibility/empty-text-under-element-cached.html
M LayoutTests/platform/glib/TestExpectations
M LayoutTests/platform/ios/TestExpectations
A
LayoutTests/platform/ios/accessibility/empty-text-under-element-cached-expected.txt
A
LayoutTests/platform/mac-wk1/accessibility/empty-text-under-element-cached-expected.txt
M Source/WebCore/accessibility/AccessibilityRenderObject.cpp
Log Message:
-----------
AX: In rare scenarios, WebKit fails to expose the text associated with
various types of elements / nodes (text, headings)
https://bugs.webkit.org/show_bug.cgi?id=252321
rdar://102025959
Reviewed by Chris Fleizach and Andres Gonzalez.
This bug happened because of this sequence:
1. We go to build a node change for an AXIsolatedObject.
2. In attempting to cache some property (i.e. AXPropertyName::StringValue),
we call into AccessibilityRenderObject::textUnderElement.
3. The document needs style recalc, so this function intentionally returns an
empty string to avoid
triggering layout which may potentially destroy renderers and AX objects
in use in this stackframe
4. We cache an empty string for the property.
This patch fixes this by removing the behavior and ASSERT listed in step
3. For a long time (~8 years), this was only a debug assert. It was "upgraded"
to actually return an empty string 2 years ago in:
https://github.com/WebKit/WebKit/commit/977f75a79bc71147cd9a434241072b720096320d
There are other ways layout can be triggered from accessibility code that we
already
have to protect against, so it doesn't make sense to workaround the issue this
way.
* LayoutTests/platform/glib/TestExpectations:
Skip new test.
* LayoutTests/accessibility/empty-text-under-element-cached-expected.txt: Added.
* LayoutTests/accessibility/empty-text-under-element-cached.html: Added.
* LayoutTests/platform/ios/TestExpectations:
Enable new test.
*
LayoutTests/platform/ios/accessibility/empty-text-under-element-cached-expected.txt:
Added.
*
LayoutTests/platform/mac-wk1/accessibility/empty-text-under-element-cached-expected.txt:
Added.
* Source/WebCore/accessibility/AccessibilityRenderObject.cpp:
(WebCore::AccessibilityRenderObject::textUnderElement const):
Canonical link: https://commits.webkit.org/260521@main
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