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This is an automatically generated e-mail. To reply, visit:
https://git.reviewboard.kde.org/r/118858/
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(Updated June 22, 2014, 7:58 a.m.)
Review request for kdelibs.
Changes
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Thanks for your comments, Christoph and Dominik! It's interesting that this
kind of crash was already discussed in 2009. I'd like to emphasize though that
the problem is not limited to the "quit via D-Bus" use case. None of the
reporters of the KUrlNavigatorCrash mention D-Bus in their reports. Lots of
other things can happen inside nested event loops: timers can fire, slots can
be called via queued connections, etc. Some of these things might delete
objects unexpectedly, and cause crashes which are very hard to reproduce.
Trying the "D-Bus quit" method for every dialog and context menu in every
application might actually reveal more real bugs that cause rare random
crashes.
I did find another nested event loop-related bug in KUrlNavigator: in
KUrlNavigator::Private::openContextMenu(): the menu, which is a child of the
KUrlNavigator, is created on the stack. This causes a crash if the navigator is
closed inside the loop because the QObject destructor tries to delete the child
object on the stack.
The fix is quite straightforward: move the menu to the heap, and use the same
"delete the menu if the QPointer is not null" idea like in
KUrlNavigator::Private::openPathSelectorMenu().
If noone sees a problem with the second version of the patch, I'll commit it in
the next few days and forward-port to KF5.
Bugs: 293863
http://bugs.kde.org/show_bug.cgi?id=293863
Repository: kdelibs
Description
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KUrlNavigator opens menus with exec() in a few places, and accesses member
variables or pointers to children after that. This can cause crashes if the
object has been deleted inside the nested event loops.
This can be fixed by using QPointers to detect if an object was deleted
already, and return immediately in that case.
Diffs (updated)
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kfile/kurlnavigator.cpp f5dfc81
kfile/kurlnavigatorbutton.cpp 6cb40b1
Diff: https://git.reviewboard.kde.org/r/118858/diff/
Testing
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Cannot reproduce the crashes any more. The menus in KUrlNavigator still work
fine for me.
Thanks,
Frank Reininghaus
