Bug 495089

Summary:	Crash with Segmentation Fault when changing rooms, sometimes
Product:	[Applications] NeoChat	Reporter:	ulterno
Component:	General	Assignee:	Tobias Fella <fella>
Status:	RESOLVED UPSTREAM
Severity:	crash	CC:	a, akselmo, carl, duha.bugs, john.kizer, nate
Priority:	NOR
Version First Reported In:	24.08.2
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:	https://codereview.qt-project.org/c/qt/qtdeclarative/+/595278	Version Fixed/Implemented In:	Qt 6.8.1
Sentry Crash Report:
Attachments:	Stack Trace using gdb including debug symbols available from debuginfod

Description ulterno 2024-10-20 13:49:06 UTC

Created attachment 175054 [details]
Stack Trace using gdb including debug symbols available from debuginfod

SUMMARY
Changing Rooms may cause a Segmentation fault.
It happened more when I opened a room with many unread messages.
Similarly, tried opening new rooms (first time entered) and had increased chances of crash

STEPS TO REPRODUCE
1. Open NeoChat
2. Change room using the left sidebar
3. Repeat until observation

OBSERVED RESULT
Crash with a Segmentation Fault

EXPECTED RESULT
No segmentation fault

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 
KDE Plasma Version: 6.2.1
KDE Frameworks Version: 6.7.0
Qt Version: 6.8.0

ADDITIONAL INFORMATION

Similar result found in master

Hardware Info:
RAM: 62.7 GiB available to the system. (< 4 GB in use at the time of crash)
CPU: AMD Ryzen 5800X with factory clock configuration

Attached Backtrace as a file because it is large

Possible Re: https://bugs.kde.org/show_bug.cgi?id=490927 ?

Comment 1 John Kizer 2024-10-21 01:54:47 UTC

I've experienced this, as well as a similar crash when scrolling in a room with many (~500) unread messages, on the same NeoChat version with Fedora 40 - same Plasma and Frameworks, but Qt 6.7.2.

Comment 2 ulterno 2024-10-21 08:30:23 UTC

Same with master branch commit 36469c6097aa8dcfc2ad1c467875051ba5f04697
Using Qt 6.8.0

Also realised over time that the same may also happen with few or no unread messages.

Comment 3 Anthony Wang 2024-10-21 18:35:28 UTC

I'm also experiencing this crash on up-to-date Arch Linux, but the crash goes away if I downgrade NeoChat to 24.05.2 but still happens with any of the 24.08.x builds.

Comment 4 Anthony Wang 2024-10-28 02:53:21 UTC

Huh, NeoChat no longer crashes for me, maybe because Arch Linux rebuilt it a few days ago for libquotient 0.9: https://gitlab.archlinux.org/archlinux/packaging/packages/neochat/-/commit/31739b60e93047189ec05adea937a19b11b58675 (On the other hand, Nheko is coredumping a lot for me now)

Comment 5 Tobias Fella 2024-11-01 21:23:10 UTC

*** Bug 495704 has been marked as a duplicate of this bug. ***

Comment 6 Akseli Lahtinen 2024-11-03 21:12:07 UTC

I feel like the crashing may be related when a timeline has collapsed joins and other items. If I open a room that has a lot of join/leave/etc. events then switch to another one, i get a crash far more reliably.

Comment 7 John Kizer 2024-11-03 22:00:18 UTC

I just tried disabling the leave/join notifications, and haven't seen a change in crash frequency, FWIW.

In Fedora 41 (Qt 6.8, libquotient 0.8.2) I'm now seeing a crash on every third or fourth room change, so a lot more than before. I've been submitting crash reports through DrKonqi, but not sure if I should continue to do so - sometimes it crashes while the first crash report is still processing, so I don't know if that many just create noise for the developers?

Comment 8 Tobias Fella 2024-11-04 14:34:05 UTC

*** Bug 495792 has been marked as a duplicate of this bug. ***

Comment 9 Nate Graham 2024-11-04 14:40:57 UTC

TL;DR: it's a Qt bug fixed by https://codereview.qt-project.org/c/qt/qtdeclarative/+/595278 in Qt 6.8.1.