Bug 470539

Summary: Screen corruption in any version starting from 22.07
Product: [Applications] okular Reporter: wilfried.philips <wilfried.philips>
Component: generalAssignee: Okular developers <okular-devel>
Status: REPORTED ---    
Severity: major    
Priority: NOR    
Version First Reported In: unspecified   
Target Milestone: ---   
Platform: Compiled Sources   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: screenshot showing screen corruption in scrollbar and dialog

Description wilfried.philips@wphilips.eu 2023-06-01 21:33:56 UTC 
Created attachment 159401 [details]
screenshot showing screen corruption in scrollbar and dialog

SUMMARY
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STEPS TO REPRODUCE
1.  on fedora36 or later install the most recent okular and start it
2. enable scrollbars
3.  scrollbars are invisible (black on black) but work
4. open the configure okular dialog
5. the dialog appears but entries towards the bottom of the screen become increasingly garbled and unreadable

OBSERVED RESULT
screen corruption in dialog and in scrollbar region

EXPECTED RESULT


SOFTWARE/OS VERSIONS

Linux + mate (fedora36,37 and 38) 
(available in About System)
Qt Version:  5 (default fedora version)

ADDITIONAL INFORMATION

The corruption is caused by commit 41e59e4f55b2c092b45afe2d8541f8198d41b534
  Set Qt::HighDpiScaleFactorRoundingPolicy::PassThrough also on Unix
    
Reverting the commit everything works again with the current master.

The comment of the commit claims to not see any adverse effect after 6 months, but this is an adverse effect.
Comment 1 wilfried.philips@wphilips.eu 2023-06-02 12:32:51 UTC 
In the mean time I discovere that some environment variable was still set to cope with earlier
QT problems (fints appearing many times too big)
The  environment variable in question was: 
QT_SCALE_FACTOR=0.585

The bug only occurs with this variable set. However without the variable, the fonts are still way too big
compared to the rest of the OS gui.