testkhtml: loader.cpp:147: virtual void 
khtml::CachedObject::deref(khtml::CachedObjectClient*): Assertion 
`m_clients.find( c )' failed.

I don't know if this related or not - but I get this on going to a number of websites including www.guardian.co.uk
[KCrash handler]
#7  0x417284b8 in Program::addControlInCurrentFrame ()
   from /usr/lib/libflash.so.0
#8  0x4172ac30 in CInputScript::ParseSetBackgroundColor ()
   from /usr/lib/libflash.so.0
#9  0x4172d1bd in CInputScript::ParseTags () from /usr/lib/libflash.so.0
#10 0x4172d5d6 in CInputScript::ParseData () from /usr/lib/libflash.so.0
#11 0x41720439 in FlashParse () from /usr/lib/libflash.so.0
#12 0x416ee083 in NPP_Write () from /usr/lib/browser-plugins/libnpflash.so
#13 0x416ef32d in Private_Write () from /usr/lib/browser-plugins/libnpflash.so
#14 0x08054902 in NSPluginInstance::NPWrite ()
#15 0x08059ec7 in NSPluginStreamBase::process ()
#16 0x08059fb0 in NSPluginStreamBase::pump ()
#17 0x0805a0c1 in NSPluginStream::data ()
#18 0x0805a1e7 in NSPluginStream::qt_invoke ()
#19 0x40b9be7e in QObject::activate_signal ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#20 0x401d8b64 in KIO::TransferJob::data () from /opt/kde3/lib/libkio.so.4
#21 0x401d8e73 in KIO::TransferJob::slotData () from /opt/kde3/lib/libkio.so.4
#22 0x40209497 in KIO::TransferJob::qt_invoke ()
   from /opt/kde3/lib/libkio.so.4
#23 0x40b9be7e in QObject::activate_signal ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#24 0x401d9222 in KIO::SlaveInterface::data () from /opt/kde3/lib/libkio.so.4
#25 0x401ef4ad in KIO::SlaveInterface::dispatch ()
   from /opt/kde3/lib/libkio.so.4
#26 0x401caa33 in KIO::SlaveInterface::dispatch ()
   from /opt/kde3/lib/libkio.so.4
#27 0x401cbc2b in KIO::Slave::gotInput () from /opt/kde3/lib/libkio.so.4
#28 0x401f284a in KIO::Slave::qt_invoke () from /opt/kde3/lib/libkio.so.4
#29 0x40b9be7e in QObject::activate_signal ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#30 0x40b9c4ad in QObject::activate_signal ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#31 0x40ef0260 in QSocketNotifier::activated ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#32 0x40bbba70 in QSocketNotifier::event ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#33 0x40b38d5f in QApplication::internalNotify ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#34 0x40b3aa83 in QApplication::notify () from /usr/lib/qt3/lib/libqt-mt.so.3
#35 0x4084d771 in KApplication::notify () from /opt/kde3/lib/libkdecore.so.4
#36 0x40b2ce76 in QEventLoop::activateSocketNotifiers ()
   from /usr/lib/qt3/lib/libqt-mt.so.3
#37 0x0805700b in QXtEventLoop::processEvents ()
#38 0x40b50e51 in QEventLoop::enterLoop () from /usr/lib/qt3/lib/libqt-mt.so.3
#39 0x40b50c96 in QEventLoop::exec () from /usr/lib/qt3/lib/libqt-mt.so.3
#40 0x40b3a94f in QApplication::exec () from /usr/lib/qt3/lib/libqt-mt.so.3
#41 0x0805b5e3 in main ()

Testcase:


<script language="javascript">

function showSideImage()
{
      window.document.images['sidead105'].src = "no-such-image";
}

function hideLink() {
      window.document.images['sidead105'].style.display="none";
}

</script>


<img onerror="hideLink()" src="http://www.kde.org/error" name="sidead105">

<script language="javascript">showSideImage();</script>

OK, I understand what's going on here. Consider where the final deref is being called from:
0: /opt/kde4/lib/libkdecore.so.4(_Z11kdBacktracei+0x3a) [0xb7628002]
1: /opt/kde4/lib/libkdecore.so.4(_Z11kdBacktracev+0x1f) [0xb7628263]
2: /opt/kde4/lib/libkhtml.so.4(_ZN5khtml12CachedObject5derefEPNS_18CachedObjectClientE+0x1f) [0xb627e96d]
3: /opt/kde4/lib/libkhtml.so.4(_ZN5khtml11CachedImage5derefEPNS_18CachedObjectClientE+0x25) [0xb628022f]
4: /opt/kde4/lib/libkhtml.so.4(_ZN5khtml11RenderImageD0Ev+0x6c) [0xb6217c2c]
5: /opt/kde4/lib/libkhtml.so.4(_ZN5khtml12RenderObject11arenaDeleteEPNS_11RenderArenaEPv+0x3d) [0xb61fe099]
6: /opt/kde4/lib/libkhtml.so.4(_ZN5khtml12RenderObject6detachEv+0x65) [0xb61fe053]
7: /opt/kde4/lib/libkhtml.so.4(_ZN5khtml15RenderContainer6detachEv+0xcd) [0xb62018ad]
8: /opt/kde4/lib/libkhtml.so.4(_ZN5khtml9RenderBox6detachEv+0x38) [0xb6203b14]
9: /opt/kde4/lib/libkhtml.so.4(_ZN3DOM8NodeImpl6detachEv+0x37) [0xb61893ed]
10: /opt/kde4/lib/libkhtml.so.4(_ZN3DOM12NodeBaseImpl6detachEv+0x5d) [0xb618aaed]
11: /opt/kde4/lib/libkhtml.so.4(_ZN3DOM11ElementImpl11recalcStyleENS_8NodeImpl11StyleChangeE+0x195) [0xb6190cb3]
12: /opt/kde4/lib/libkhtml.so.4(_ZN3DOM15HTMLElementImpl11recalcStyleENS_8NodeImpl11StyleChangeE+0x21) [0xb61b6a4d]
13: /opt/kde4/lib/libkhtml.so.4(_ZN3DOM11ElementImpl11recalcStyleENS_8NodeImpl11StyleChangeE+0x2c4) [0xb6190de2]
14: /opt/kde4/lib/libkhtml.so.4(_ZN3DOM15HTMLElementImpl11recalcStyleENS_8NodeImpl11StyleChangeE+0x21) [0xb61b6a4d]
15: /opt/kde4/lib/libkhtml.so.4(_ZN3DOM11ElementImpl11recalcStyleENS_8NodeImpl11StyleChangeE+0x2c4) [0xb6190de2]
16: /opt/kde4/lib/libkhtml.so.4(_ZN3DOM15HTMLElementImpl11recalcStyleENS_8NodeImpl11StyleChangeE+0x21) [0xb61b6a4d]
17: /opt/kde4/lib/libkhtml.so.4(_ZN3DOM12DocumentImpl11recalcStyleENS_8NodeImpl11StyleChangeE+0x36f) [0xb617bc8d]
18: /opt/kde4/lib/libkhtml.so.4(_ZN3DOM12DocumentImpl15updateRenderingEv+0x47) [0xb617bd77]
19: /opt/kde4/lib/libkhtml.so.4(_ZN3DOM12DocumentImpl24updateDocumentsRenderingEv+0x84) [0xb617be04]
20: /opt/kde4/lib/libkhtml.so.4(_ZN3KJS6Window20afterScriptExecutionEv+0x19) [0xb62dbe1b]
21: /opt/kde4/lib/libkhtml.so.4(_ZN3KJS15JSEventListener11handleEventERN3DOM5EventE+0x3fa) [0xb630e88e]
22: /opt/kde4/lib/libkhtml.so.4(_ZN3KJS19JSLazyEventListener11handleEventERN3DOM5EventE+0x45) [0xb630efb3]
23: /opt/kde4/lib/libkhtml.so.4(_ZN3DOM8NodeImpl17handleLocalEventsEPNS_9EventImplEb+0xdf) [0xb6188c1b]
24: /opt/kde4/lib/libkhtml.so.4(_ZN3DOM8NodeImpl20dispatchGenericEventEPNS_9EventImplERi+0x1b3) [0xb6187fa1]
25: /opt/kde4/lib/libkhtml.so.4(_ZN3DOM8NodeImpl13dispatchEventEPNS_9EventImplERib+0x5a) [0xb6187d5e]
26: /opt/kde4/lib/libkhtml.so.4(_ZN3DOM8NodeImpl17dispatchHTMLEventEibb+0x7a) [0xb61882a8]
27: /opt/kde4/lib/libkhtml.so.4(_ZN5khtml11RenderImage14notifyFinishedEPNS_12CachedObjectE+0x97) [0xb6219197]
28: /opt/kde4/lib/libkhtml.so.4(_ZN5khtml11CachedImage5errorEiPKc+0x147) [0xb628131d] <--- see this?

This loop is iterating over the clients dictionary, but it got changed in the process! I am not quite sure of how to fix this: this case removes items, and I know how to address that, but I am not sure of what to do if new ones are added. Ideas? (Perhaps there is a way of making the iteration safe, or may be the event need to be delayed somehow..)

Actually, even before that --- when we're inside notifyFinished, we get deleted!  I guess that should be addressed by doing the deref on cached image first, so the null is set properly for the destructor, though even that is nasty, and still leaves the iteration issue. (It also seems that the arena needs valgrind annotations)

Created attachment 11378 [details]
Proposed fix

This should fix the crash; I am not quite comfortable with the issue of the
changes to client set, but it's safer than I thought...

I'll take your word for it and wait for the next RPM, I'm just a user, really 
pleased to have KDE


On Wednesday 08 June 2005 22:40, Maksim Orlovich wrote:
[bugs.kde.org quoted mail]

Created attachment 11562 [details]
better patch - WC merge

This, IMHO, is a better fix, extracted from WebCore (not the current code, but
a slightly older version; I'd rather not do two changes at once); as it fixes a
lot more bugs.

SVN commit 428727 by orlovich:

Merge in http://www.cs.cornell.edu/~maksim/WC/changesets/1771.html 
from WC. This prevent recursion bugs happening in onload events.
(Note: the current WebCore code is different, and I know at least 
some bugs it fixes, but I don't want to make 2 
changes at once. Better get this tested for a bit before moving on)

Fixes #107052, and the crash in #99480, as well as some synthetic onload
testcases I cooked up. Some testcases upcoming up
BUG:107052
CCBUG:99480




 M  +3 -0      html/html_documentimpl.cpp  
 M  +35 -5     rendering/render_image.cpp  
 M  +3 -0      rendering/render_image.h  
 M  +61 -1     xml/dom_docimpl.cpp  
 M  +10 -0     xml/dom_docimpl.h  

*** Bug 109888 has been marked as a duplicate of this bug. ***