Comment 22 for bug 457731

Created attachment 84935
Proposed patch: cancel construction before quit

I can confirm Christoph's patch works as described, but I don't think it's a good user experience. You try to quit the program, and the button responds but it doesn't quit. There's no indication that the construct mode has to be canceled first.

Here's an update of the patch that escapes the nested event loop before quitting by canceling the construction. It's definitely an abuse of queryClose(), and I don't understand the Kig code well enough to guarantee it will always work. In particular, is it possible for there to be more than two levels of nested event loops, i.e. some other mode invoked from within a construct mode? Still, it does solve this particular crash, and makes the program behave as the user expects.

I don't see another way to do it, short of getting rid of the event loop nesting altogether, which seems to be the root of the problem. Although, a halfway but reliable alternative would be to cancel the construction but return false from KigPart::queryClose(). That is, the first time you try to quit, it just cancels the mode; the second time it really quits.