[SOLVED] chromium unresponsive when opening preferences

Question

When opening preferences in chromium, a new tab appears but it is not populated and the tab becomes unresponsive. Obviously, this is a deal-breaker and I need some help in fixing it.
I observed that after opening preferences, a new ktradertest process (I use KDE) is eating 100% cpu. ktradertest is spawned by xdg-settings, which is spawned by the original chromium process, trying to determine if it is the default browser. So the root problem is that ktradertest never returns. This is reproducible by running "ktradertest text/html Application" in a terminal.
A new user account did not exhibit the same behavior. Running ktradertest through either strace or gdb also failed to reproduce the problem. Attaching to the hung process yields the following stack trace:
#0 0x00007f4a429b81c5 in ?? () from /usr/lib/libGL.so.1
#1 0x00007f4a40da83ec in ?? () from /usr/lib/libnvidia-tls.so.290.10
#2 0x00007f4a46715d32 in KConfigINIBackEnd::parseSingleConfigFile(QFile&, QMap<KEntryKey, KEntry>*, bool, bool) () from /opt/kde/lib/libkdecore.so.4
#3 0x00007f4a46737293 in KConfigINIBackEnd::parseConfigFiles() () from /opt/kde/lib/libkdecore.so.4
#4 0x00007f4a467341eb in KConfigBase::parseConfigFiles() () from /opt/kde/lib/libkdecore.so.4
#5 0x00007f4a467157d5 in KConfig::reparseConfiguration() () from /opt/kde/lib/libkdecore.so.4
#6 0x00007f4a46718ec7 in KConfig::KConfig(QString const&, bool, bool, char const*) () from /opt/kde/lib/libkdecore.so.4
#7 0x00007f4a46c4174f in KServiceTypeProfile::initStatic() () from /opt/kde/lib/libkio.so.4
#8 0x00007f4a46c41ae1 in KServiceTypeProfile::serviceTypeProfile(QString const&, QString const&) () from /opt/kde/lib/libkio.so.4
#9 0x00007f4a46c422bb in KServiceTypeProfile::offers(QString const&, QString const&) () from /opt/kde/lib/libkio.so.4
#10 0x00007f4a46c44141 in KTrader::query(QString const&, QString const&, QString const&, QString const&) const () from /opt/kde/lib/libkio.so.4
#11 0x00000000004016ff in ?? ()
#12 0x00007f4a4554b38d in __libc_start_main () from /lib/libc.so.6
So it seems that some configuration file is causing the problem, but I've tested every one I can think of without success.
Last edited by jrmrjnck (2012-01-11 00:53:10)

Answer 1

It seems that ktradertest is part of kdelibs3 and is not included in recent releases of KDE4, which explains why I couldn't find any information about it. There was only one old application using kdelibs3, so I got rid of all KDE3 stuff and the problem is solved. Since ktradertest is not intended to be run in a modern KDE4 environment, it's understandable that it's unstable and failing in this weird way.
However, it seems that xdg-settings should not be using it. xdg-settings also calls xdg-mime, which does perform a version check and uses ktraderclient in the case of KDE4. It seems that xdg-settings should also perform that check and not use ktradertest, which probably just returns a "command not found" on most desktops.