Bug 101791 – REGRESSION(r130643): ASSERTION FAILED:!isDeletedBucket(*(lookupForWriting(Extractor::extract(entry)).first)) when running DRT in debug mode

• Component: CSS
• Status: RESOLVED FIXED

[Roger Fong]

The problem occurs when calling WebKitCreateInstance.

The associated hashtable tries to resize and the reinsert objects but one of the object's values is CLSID_NULL for some reason which indicates that it has been deleted already, and the !isDeletedBucket assertion fails.

Here is the stack trace:

>	WebKit.dll!WTF::HashTable<_GUID,WTF::KeyValuePair<_GUID,COMPtr<IClassFactory> >,WTF::KeyValuePairKeyExtractor<WTF::KeyValuePair<_GUID,COMPtr<IClassFactory> > >,CLSIDHash,WTF::HashMapValueTraits<CLSIDHashTraits,WTF::HashTraits<COMPtr<IClassFactory> > >,CLSIDHashTraits>::reinsert(WTF::KeyValuePair<_GUID,COMPtr<IClassFactory> > & entry={...})  Line 953 + 0x51 bytes	C++
 	WebKit.dll!WTF::HashTable<_GUID,WTF::KeyValuePair<_GUID,COMPtr<IClassFactory> >,WTF::KeyValuePairKeyExtractor<WTF::KeyValuePair<_GUID,COMPtr<IClassFactory> > >,CLSIDHash,WTF::HashMapValueTraits<CLSIDHashTraits,WTF::HashTraits<COMPtr<IClassFactory> > >,CLSIDHashTraits>::rehash(int newTableSize=16)  Line 1135	C++
 	WebKit.dll!WTF::HashTable<_GUID,WTF::KeyValuePair<_GUID,COMPtr<IClassFactory> >,WTF::KeyValuePairKeyExtractor<WTF::KeyValuePair<_GUID,COMPtr<IClassFactory> > >,CLSIDHash,WTF::HashMapValueTraits<CLSIDHashTraits,WTF::HashTraits<COMPtr<IClassFactory> > >,CLSIDHashTraits>::expand()  Line 1107	C++
 	WebKit.dll!WTF::HashTable<_GUID,WTF::KeyValuePair<_GUID,COMPtr<IClassFactory> >,WTF::KeyValuePairKeyExtractor<WTF::KeyValuePair<_GUID,COMPtr<IClassFactory> > >,CLSIDHash,WTF::HashMapValueTraits<CLSIDHashTraits,WTF::HashTraits<COMPtr<IClassFactory> > >,CLSIDHashTraits>::add<WTF::HashMapTranslator<WTF::HashMapValueTraits<CLSIDHashTraits,WTF::HashTraits<COMPtr<IClassFactory> > >,CLSIDHash>,_GUID,COMPtr<IClassFactory> >(const _GUID & key={...}, const COMPtr<IClassFactory> & extra={...})  Line 893	C++
 	WebKit.dll!WTF::HashMap<_GUID,COMPtr<IClassFactory>,CLSIDHash,CLSIDHashTraits,WTF::HashTraits<COMPtr<IClassFactory> > >::inlineAdd(const _GUID & key={...}, const COMPtr<IClassFactory> & mapped={...})  Line 334 + 0x14 bytes	C++
 	WebKit.dll!WTF::HashMap<_GUID,COMPtr<IClassFactory>,CLSIDHash,CLSIDHashTraits,WTF::HashTraits<COMPtr<IClassFactory> > >::add(const _GUID & key={...}, const COMPtr<IClassFactory> & mapped={...})  Line 361 + 0x14 bytes	C++
 	WebKit.dll!classFactory(const _GUID & clsid={...})  Line 54 + 0x21 bytes	C++
 	WebKit.dll!WebKitCreateInstance(const _GUID & rclsid={...}, IUnknown * pUnkOuter=0x00000000, const _GUID & riid={...}, void * * ppvObject=0x002efb64)  Line 64 + 0xd bytes	C++
 	DumpRenderTree.dll!dllLauncherEntryPoint(int argc=2, const char * * argv=0x00141ba0)  Line 1392 + 0x1a bytes	C++
 	DumpRenderTree.exe!main(int argc=2, const char * * argv=0x00141ba0)  Line 206 + 0x10 bytes	C++
 	DumpRenderTree.exe!__tmainCRTStartup()  Line 597 + 0x17 bytes	C

Work around: 
Following http://trac.webkit.org/changeset/132302, by reverting the minimum hash table size back to 64 this problem can be avoided temporarily.
As with the r132302 this will need a proper fix at some point.

[Roger Fong]

Created attachment 173356 [details]
patch

[WebKit Review Bot]

Comment on attachment 173356 [details]
patch

Attachment 173356 [details] did not pass chromium-ews (chromium-xvfb):
Output: http://queues.webkit.org/results/14794079

[Alexey Proskuryakov]

This probably needs a FIXME, like r132302 had.

[Roger Fong]

Created attachment 173791 [details]
patch

added a FIXME

[Darin Adler]

Comment on attachment 173791 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=173791&action=review

> Source/WebKit/win/WebKitCOMAPI.cpp:47
> +    // FIXME: This is a work around - https://bugs.webkit.org/show_bug.cgi?id=101791

We will need a real fix soon!

Might be nicer if the FIXME made it clearer how this works around the bug. Typically we frown on putting bug URLs into the code.

[Roger Fong]

Commited http://trac.webkit.org/changeset/134472
with FIXME clarifications.

[Eric Seidel (no email)]

Attachment 173791 [details] was posted by a committer and has review+, assigning to Roger Fong for commit.