davidedmundson
commented
9 years ago Backtrace for future me
Thread 1 (Thread 0x7f32a9cb47c0 (LWP 1667)): [KCrash Handler]
Closed star-buck closed 8 years ago
davidedmundson
commented
9 years ago Backtrace for future me
Thread 1 (Thread 0x7f32a9cb47c0 (LWP 1667)): [KCrash Handler]
davidedmundson
commented
9 years ago Interestingly we have the same crash reported in a completely unrelated area of Plasma. https://bugs.kde.org/show_bug.cgi?id=338890
We delete a QQmlEngine and then the same thing is happening.
davidedmundson
commented
9 years ago The underlying problem is super deep in Qt's JS engine.
I have a patch that bodges round it in kwins KCM changing our behaviour so we don't hit it. https://paste.kde.org/pv8bqqz8k I opened the kcmshell5 15 times in a row and it all seemed fine.
I'm pretty close to fixing it properly, which I think is worth doing given we've seen the same crash elsewhere but I need another day on it.
mgraesslin
commented
9 years ago The workaround seems fine to me independent of whether we get a fix into Qt or not (given that it's still some time and can hit many users).
davidedmundson
commented
9 years ago ok, is that a ship it? and I'll make sure it gets into netrunner packaging too
mgraesslin
commented
9 years ago ok, is that a ship it?
yes, for Plasma/5.2 branch
hsitter
commented
9 years ago 
star-buck
commented
9 years ago still crashing: you open window deco kcm, you have two or more auorae themes installed, you pick one and apply. Then you close system settings and re-open window deco kcm again, now selecting (but not applying) the other aurorae theme, then close system settings window (with "X" window deco button). The popup "Apply, Discard,Cancel" comes up since you have not "applied" yet, choose "Discard" and the crash popup appears after system settings window closed.
star-buck
commented
9 years ago system settings is also crashing when:
but switching from breeze to qtcurve works without crash
davidedmundson
commented
9 years ago Yeah, I've seen it :(
I thought my bodge was enough but clearly doesn't work enough with enough Auorae themes.
I have a definite patch for QtDeclaratiave that fixes the problem at the cause: https://paste.kde.org/pmx8ewy10 and with this I haven't seen the crash with this.
hsitter
commented
9 years ago davidedmundson
commented
9 years ago Just tested that build on Netrunner. Apparently it's not fixing it. Sorry.
Will spend another day on this. Stupid bloody thing.
davidedmundson
commented
9 years ago Somehow that patch applied is off by one line.
The regexpcache should move not the regexpallocator.
It's possible I uploaded the wrong thing? I did have to redo it from the test machine to my laptop to upload.. or maybe it got messed up when we made the packaging.
Either way, it definitely has the wrong thing in debian/patches/fix-dtor-crash.patch compared with what I tested.
Harald could you rebuild with this. https://paste.kde.org/pnmb47vec
hsitter
commented
9 years ago star-buck
commented
9 years ago seems fixed.
star-buck
commented
9 years ago re-opened, steps to reproduce a crash:
davidedmundson
commented
9 years ago I fixed it in a patch that went into Netrunner's version of Qt.
That patch does not seem to be in Kubuntu's version of Qt.
hsitter
commented
9 years ago upstream ref?
star-buck
commented
9 years ago @notmart : with David on the phone, can you have a look and let @apachelogger know?
notmart
commented
9 years ago sure
notmart
commented
9 years ago that patch should be definitely upstreamed... A problem is that it is a crash that seems to be very difficult to reproduce in a simple test, that is something that is pretty much required to push the change in Qt. this small app is as near i went replicating what the decoration kcm is doing http://www.notmart.org/misc/qregexpcache.tar.bz2 but doesn't seem to crash
star-buck
commented
9 years ago So which patches need to be reapplied to which packages again by Harald to make it work?
notmart
commented
9 years ago star-buck
commented
9 years ago okay, @apachelogger : lets try packaging this?
hsitter
commented
9 years ago hsitter
commented
9 years ago FWIW, I suggest to not close this issue if it works. This is going to crop up again for netrunner17 unless it gets resolved upstream, so we best not forget.
star-buck
commented
9 years ago @notmart: So now it crashes right away as soon as I try to open Window Decoration kcm...
star-buck
commented
9 years ago Here is what I found:
mgraesslin
commented
8 years ago To my knowledge all crashers of window decoration configuration module are fixed with 5.4.3
star-buck
commented
8 years ago it still crashed on netrunner with plasma 5.4.3, but i cannot seem to reproduce it. I changed something and clicked "back" button, then it crashed... will close for now and reopen if happens again.
steps to reproduce crash: