Bug 162166 – Update XHTMLParser to recognize "-//W3C//DTD MathML 2.0//EN" public identifier

• Component: DOM
• Status: RESOLVED FIXED

[Chris Dumez]

XHTMLParser does not recognize some of the public identifiers in the specification:
- https://html.spec.whatwg.org/#parsing-xhtml-documents

In particular, we were missing the following ones: "-//W3C//DTD MathML 2.0//EN" and "-//WAPFORUM//DTD XHTML Mobile 1.0//EN".

Firefox recognizes those properly.

[Chris Dumez]

Created attachment 289237 [details]
Patch

[Alex Christensen]

Comment on attachment 289237 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=289237&action=review

> Source/WebCore/xml/parser/XMLDocumentParserLibxml2.cpp:1315
>          || (extId == "-//W3C//DTD XHTML 1.1 plus MathML 2.0//EN")
>          || (extId == "-//W3C//DTD XHTML 1.1 plus MathML 2.0 plus SVG 1.1//EN")
> +        || (extId == "-//W3C//DTD MathML 2.0//EN")
>          || (extId == "-//WAPFORUM//DTD XHTML Mobile 1.0//EN")

This code could be much more efficient.  Right now we unnecessarily allocate and copy a String, then do many unnecessary comparisons.  We should do something like isSpecialScheme, except we shouldn't even need to calculate the length first because it seems to be null-terminated.

[Build Bot]

Comment on attachment 289237 [details]
Patch

Attachment 289237 [details] did not pass mac-debug-ews (mac):
Output: http://webkit-queues.webkit.org/results/2106869

New failing tests:
imported/w3c/web-platform-tests/html/the-xhtml-syntax/parsing-xhtml-documents/xhtml-mathml-dtd-entity-support.htm

[Build Bot]

Created attachment 289244 [details]
Archive of layout-test-results from ews117 for mac-yosemite

The attached test failures were seen while running run-webkit-tests on the mac-debug-ews.
Bot: ews117  Port: mac-yosemite  Platform: Mac OS X 10.10.5

[Chris Dumez]

Looks like the new test hits an assertion on debug builds:
xception Type:        EXC_BAD_ACCESS (SIGSEGV)
Exception Codes:       KERN_INVALID_ADDRESS at 0x00000000bbadbeef

VM Regions Near 0xbbadbeef:
--> 
    __TEXT                 0000000102d4a000-0000000102e0c000 [  776K] r-x/rwx SM=COW  /Volumes/VOLUME/*

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   com.apple.JavaScriptCore      	0x00000001043a05d7 WTFCrash + 39
1   com.apple.WebCore             	0x000000010bc7bd2c WebCore::convertUTF16EntityToUTF8(unsigned short const*, unsigned long, char*, unsigned long) + 188 (XMLDocumentParserLibxml2.cpp:1216)
2   com.apple.WebCore             	0x000000010bc7bbed WebCore::getXHTMLEntity(unsigned char const*) + 157 (XMLDocumentParserLibxml2.cpp:1229)
3   com.apple.WebCore             	0x000000010bc7a577 WebCore::getEntityHandler(void*, unsigned char const*) + 295 (XMLDocumentParserLibxml2.cpp:1276)
4   libxml2.2.dylib               	0x00007fff891300a8 xmlParseEntityRef + 225
5   libxml2.2.dylib               	0x00007fff8912f79b xmlParseReference + 194
6   libxml2.2.dylib               	0x00007fff891368ef xmlParseTryOrFinish + 5405
7   libxml2.2.dylib               	0x00007fff891351dd xmlParseChunk + 901
8   com.apple.WebCore             	0x000000010bc77ca8 WebCore::XMLDocumentParser::doWrite(WTF::String const&) + 408 (XMLDocumentParserLibxml2.cpp:690)
9   com.apple.WebCore             	0x000000010bc74988 WebCore::XMLDocumentParser::append(WTF::RefPtr<WTF::StringImpl>&&) + 312 (XMLDocumentParser.cpp:122)
10  com.apple.WebCore             	0x0000000109ac7a4c WebCore::Document::setContent(WTF::String const&) + 108 (Document.cpp:1402)
11  com.apple.WebCore             	0x0000000109b9c4bd WebCore::DOMParser::parseFromString(WTF::String const&, WTF::String const&, int&) + 285 (DOMParser.cpp:40)
12  com.apple.WebCore             	0x000000010a5628ae WebCore::jsDOMParserPrototypeFunctionParseFromString(JSC::ExecState*) + 1038 (JSDOMParser.cpp:187)

[Chris Dumez]

(In reply to comment #2)
> Comment on attachment 289237 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=289237&action=review
> 
> > Source/WebCore/xml/parser/XMLDocumentParserLibxml2.cpp:1315
> >          || (extId == "-//W3C//DTD XHTML 1.1 plus MathML 2.0//EN")
> >          || (extId == "-//W3C//DTD XHTML 1.1 plus MathML 2.0 plus SVG 1.1//EN")
> > +        || (extId == "-//W3C//DTD MathML 2.0//EN")
> >          || (extId == "-//WAPFORUM//DTD XHTML Mobile 1.0//EN")
> 
> This code could be much more efficient.  Right now we unnecessarily allocate
> and copy a String, then do many unnecessary comparisons.  We should do
> something like isSpecialScheme, except we shouldn't even need to calculate
> the length first because it seems to be null-terminated.

It can probably be more efficient yes, but this is the common pattern in this file to convert xmlChar* to String first using toString, which does a reinterpret_cast and a String::fromUtf8(). I'd rather not do the refactoring in the same patch.

[Chris Dumez]

Created attachment 289246 [details]
Patch

[Chris Dumez]

Comment on attachment 289244 [details]
Archive of layout-test-results from ews117 for mac-yosemite

Dealing with the debug crash via Bug 162215 since it is not related to my code change (the new test hits an assertion in debug builds without my change).

[Chris Dumez]

Created attachment 289251 [details]
Patch

[WebKit Commit Bot]

Comment on attachment 289251 [details]
Patch

Clearing flags on attachment: 289251

Committed r206118: <http://trac.webkit.org/changeset/206118>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Chris Dumez]

*** Bug 162215 has been marked as a duplicate of this bug. ***