Bug 444231

Summary: Illegal null property access resulting in `TypeError`s
Product: [Applications] plasma-systemmonitor Reporter: ratijas <me>
Component: generalAssignee: KSysGuard Developers <ksysguard-bugs>
Status: RESOLVED FIXED    
Severity: minor CC: ahiemstra, nate, plasma-bugs-null
Priority: NOR    
Version First Reported In: master   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description ratijas 2021-10-22 09:34:17 UTC
SUMMARY
When switching pages, loading some of them generates QML/JS `TypeError`s. It only happens on some pages, and only during first time loading -- I guess after that they get cached or something.

I took a quick look at the code, but couldn't figure it out immediately, hence filing a bug for later(tm).

Also, it doesn't seem to break stuff. I think properties eventually receive intended values during same update cycle of event loop, before they get a chance to display inconsistency on a screen.

STEPS TO REPRODUCE
1. Launch plasma-systemmonitor.
2. Select pages from the sidebar, one by one.

OBSERVED RESULT

    file::/main.qml:25: TypeError: Cannot read property 'title' of null
    file::/main.qml:81: TypeError: Value is null and could not be converted to an object
    qrc:/GlobalMenu.qml:32: TypeError: Value is null and could not be converted to an object

EXPECTED RESULT
No errors

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
KDE Plasma Version: 5.23.80
KDE Frameworks Version: 5.88.0
Qt Version: 5.15.2
Kernel Version: 5.14.12-arch1-1 (64-bit)
Graphics Platform: X11
Processors: 8 × Intel® Core™ i7-6700HQ CPU @ 2.60GHz
Memory: 15.6 GiB of RAM
Graphics Processor: NVIDIA GeForce GTX 970M/PCIe/SSE2

ADDITIONAL INFORMATION
Comment 1 Arjen Hiemstra 2024-06-06 16:08:14 UTC
I'm not getting any more TypeErrors with Plasma 6.1. I'm going to mark this as resolved, feel free to reopen if it still happens for you.