AX: AccessibilitySlider::inputElement should check if the renderer has become null

• Component: Accessibility
• Status: RESOLVED FIXED

[Tyler Wilcock]

After https://bugs.webkit.org/show_bug.cgi?id=235715, we no longer call the update version of children from logging. This has made accessibility/mac/spinbutton-valuedescription.html a constant failure in debug mode only, since the logging is trying to print an AX tree that is out of sync with the DOM. This test uses JS to remove an <input> renderer + node.

Exception Type:        EXC_BAD_ACCESS (SIGSEGV)
Exception Codes:       KERN_INVALID_ADDRESS at 0x000000000000003c

0   com.apple.WebCore             	0x00000001af545e0c WebCore::RenderObject::RenderObjectBitfields::isAnonymous() const + 12 (RenderObject.h:888)
1   com.apple.WebCore             	0x00000001af545dee WebCore::RenderObject::isAnonymous() const + 30 (RenderObject.h:391)
2   com.apple.WebCore             	0x00000001af530f0c WebCore::RenderObject::node() const + 28 (RenderObject.h:465)
3   com.apple.WebCore             	0x00000001afa53186 WebCore::AccessibilitySlider::inputElement() const + 38 (AccessibilitySlider.cpp:150)
4   com.apple.WebCore             	0x00000001afa53149 WebCore::AccessibilitySlider::getAttribute(WebCore::QualifiedName const&) const + 25 (AccessibilitySlider.cpp:108)
5   com.apple.WebCore             	0x00000001afa0e958 WebCore::AccessibilityObject::identifierAttribute() const + 72 (AccessibilityObject.cpp:2984)
6   com.apple.WebCore             	0x00000001af988ac1 WebCore::operator<<(WTF::TextStream&, WebCore::AXCoreObject const&) + 145 (AXLogger.cpp:487)
7   com.apple.WebCore             	0x00000001af9890af WebCore::AXLogger::add(WTF::TextStream&, WTF::RefPtr<WebCore::AXCoreObject, WTF::RawPtrTraits<WebCore::AXCoreObject>, WTF::DefaultRefDerefTraits<WebCore::AXCoreObject> > const&, bool) + 95 (AXLogger.cpp:100)
8   com.apple.WebCore             	0x00000001af989116 WebCore::AXLogger::add(WTF::TextStream&, WTF::RefPtr<WebCore::AXCoreObject, WTF::RawPtrTraits<WebCore::AXCoreObject>, WTF::DefaultRefDerefTraits<WebCore::AXCoreObject> > const&, bool) + 198 (AXLogger.cpp:104)
9   com.apple.WebCore             	0x00000001af989116 WebCore::AXLogger::add(WTF::TextStream&, WTF::RefPtr<WebCore::AXCoreObject, WTF::RawPtrTraits<WebCore::AXCoreObject>, WTF::DefaultRefDerefTraits<WebCore::AXCoreObject> > const&, bool) + 198 (AXLogger.cpp:104)
10  com.apple.WebCore             	0x00000001af989116 WebCore::AXLogger::add(WTF::TextStream&, WTF::RefPtr<WebCore::AXCoreObject, WTF::RawPtrTraits<WebCore::AXCoreObject>, WTF::DefaultRefDerefTraits<WebCore::AXCoreObject> > const&, bool) + 198 (AXLogger.cpp:104)
11  com.apple.WebCore             	0x00000001af98a044 WebCore::operator<<(WTF::TextStream&, WebCore::AXObjectCache&) + 164 (AXLogger.cpp:528)
12  com.apple.WebCore             	0x00000001af989f40 WebCore::AXLogger::log(WebCore::AXObjectCache&) + 80 (AXLogger.cpp:146)
13  com.apple.WebCore             	0x00000001af994ce0 WebCore::AXObjectCache::updateIsolatedTree(WTF::Vector<std::__1::pair<WTF::RefPtr<WebCore::AXCoreObject, WTF::RawPtrTraits<WebCore::AXCoreObject>, WTF::DefaultRefDerefTraits<WebCore::AXCoreObject> >, WebCore::AXObjectCache::AXNotification>, 0ul, WTF::CrashOnOverflow, 16ul, WTF::FastMalloc> const&) + 80 (AXObjectCache.cpp:3327)
14  com.apple.WebCore             	0x00000001af98d138 WebCore::AXObjectCache::notificationPostTimerFired() + 1032 (AXObjectCache.cpp:1150)


This logging is not enabled in release, so it's not a problem there.

[Radar WebKit Bug Importer]

<rdar://problem/88188151>

[Tyler Wilcock]

Created attachment 450238 [details]
Patch

[Tyler Wilcock]

Created attachment 450265 [details]
Patch

[Tyler Wilcock]

Created attachment 450266 [details]
Patch

[EWS]

Committed r288774 (246555@main): <https://commits.webkit.org/246555@main>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 450266 [details].