SUMMARY

Dolphin fails to restore window state (on restart) to maximized when running on wayland


STEPS TO REPRODUCE

1. Maximize dophin window (Ref. screenshot 1)
2. Close it
3. Reopen dolphin (Note: Now the application seems to be opened with a size which would be if it was started maximized, but it does not actually start maximized, as is evident from titlebar buttons' state) (Ref. screenshot 2)
4. Try to maximize window by clicking on relevant button in titlebar. Window is resized in a weird way (Ref. screenshot 3). If the window is resized (dragging from edges) before maximizing, it is maximized properly.


EFFECTS OF BEHAVIOR MENTIONED ABOVE

1. Since the application window is started with a size of a maximized application (while not actually maximized; evident from buttons on the titlebar), it cannot be restored to a smaller size.
2. Since, to the window manager, the window is not maximized, shown window (i) has border around it and (ii) is shown with a titlebar even if showing titlebar for maximized windows is disabled.


SOFTWARE/OS/HARDWARE VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 5.16.3
KDE Frameworks Version: 5.59.0
Qt Version: 5.13.0
Kernel Version: 4.19.57-1-lts
OS Type: 64-bit
Processors: 4 × Intel® Core™ i5-6500 CPU @ 3.20GHz
Memory: 14.6 GiB


ADDITIONAL INFORMATION

This report originates from: https://bugs.kde.org/show_bug.cgi?id=409919

Another related bug report: https://bugs.kde.org/show_bug.cgi?id=391621