412588 - ASSERTION: |First()| called on an empty string with badly nested { in external stylesheet

Status: RESOLVED WORKSFORME

(Core :: CSS Parsing and Computation, defect)

Description

[Martijn Wargers (dead)]

Attachment: testcase

I'm getting this assertion at the url with current trunk build:
###!!! ASSERTION: |First()| called on an empty string: 'mLength > 0', file c:\mo
zilla-build\mozilla\_firefox\dist\include\string\nsTSubstring.h, line 207

See testcase, the assertion is caused by the external stylesheet, which has this content:
@media print {{}
a { }
a{font-size: 200%;}

Backtrace from the assertion:
 	ntdll.dll!_DbgBreakPoint@0() 	
>	xpcom_core.dll!Break(const char * aMsg=0x0012f09c)  Line 480	C++
 	xpcom_core.dll!NS_DebugBreak_P(unsigned int aSeverity=1, const char * aStr=0x02209fc4, const char * aExpr=0x02209fe8, const char * aFile=0x021dab90, int aLine=207)  Line 358 + 0xc bytes	C++
 	gklayout.dll!nsAString_internal::First()  Line 207 + 0x25 bytes	C++
 	gklayout.dll!NonMozillaVendorIdentifier(const nsAString_internal & ident={...})  Line 802 + 0x8 bytes	C++
 	gklayout.dll!CSSParserImpl::ParseAtRule(unsigned int & aErrorCode=0, void (nsICSSRule *, void *)* aAppendFunc=0x01a8a8d0, void * aData=0x0410b488)  Line 1309 + 0xc bytes	C++
 	gklayout.dll!CSSParserImpl::Parse(nsIUnicharInputStream * aInput=0x05d2d768, nsIURI * aSheetURI=0x05239880, nsIURI * aBaseURI=0x05239880, nsIPrincipal * aSheetPrincipal=0x060b4660, unsigned int aLineNumber=1, int aAllowUnsafeRules=0, nsICSSStyleSheet * & aResult=0x00000000)  Line 776	C++
 	gklayout.dll!CSSLoaderImpl::ParseSheet(nsIUnicharInputStream * aStream=0x05d2d768, SheetLoadData * aLoadData=0x0607a108, int & aCompleted=0)  Line 1511 + 0x7d bytes	C++
 	gklayout.dll!SheetLoadData::OnStreamComplete(nsIUnicharStreamLoader * aLoader=0x05e6a0c8, nsISupports * aContext=0x00000000, unsigned int aStatus=0, nsIUnicharInputStream * aDataStream=0x05d2d768)  Line 867 + 0x1a bytes	C++
 	necko.dll!nsUnicharStreamLoader::OnStopRequest(nsIRequest * request=0x0676b650, nsISupports * ctxt=0x00000000, unsigned int aStatus=0)  Line 164	C++
 	necko.dll!nsBaseChannel::OnStopRequest(nsIRequest * request=0x060c13b8, nsISupports * ctxt=0x00000000, unsigned int status=0)  Line 620	C++
 	necko.dll!nsInputStreamPump::OnStateStop()  Line 577	C++
 	necko.dll!nsInputStreamPump::OnInputStreamReady(nsIAsyncInputStream * stream=0x05049f10)  Line 401 + 0xb bytes	C++
 	xpcom_core.dll!nsInputStreamReadyEvent::Run()  Line 112	C++
 	xpcom_core.dll!nsThread::ProcessNextEvent(int mayWait=1, int * result=0x0012f95c)  Line 511	C++
 	xpcom_core.dll!NS_ProcessNextEvent_P(nsIThread * thread=0x00e2d910, int mayWait=1)  Line 227 + 0x16 bytes	C++
 	gkwidget.dll!nsBaseAppShell::Run()  Line 154 + 0xc bytes	C++
 	tkitcmps.dll!nsAppStartup::Run()  Line 181 + 0x1c bytes	C++
 	xul.dll!XRE_main(int argc=1, char * * argv=0x00e2a9b8, const nsXREAppData * aAppData=0x00e2afb8)  Line 3207 + 0x25 bytes	C++
 	firefox.exe!NS_internal_main(int argc=1, char * * argv=0x00e2a9b8)  Line 158 + 0x12 bytes	C++
 	firefox.exe!wmain(int argc=1, unsigned short * * argv=0x00e288b0)  Line 55 + 0xd bytes	C++
 	firefox.exe!__tmainCRTStartup()  Line 583 + 0x19 bytes	C
 	firefox.exe!wmainCRTStartup()  Line 403	C
 	kernel32.dll!_BaseProcessStart@4()  + 0x23 bytes

Comment 1

[Jesse Ruderman]

WFM.  Martijn, are you still seeing this?

Comment 2

[Jesse Ruderman]

Crashtest: http://hg.mozilla.org/mozilla-central/rev/b64a7e4a35e2