Bug 466850

SUMMARY
I downloaded an empty log file named stdio (no extension). When I double-click the file in Dolphin a dialog appears "Choose an application to open 'stdio'. But there's no way to choose an application with the keyboard. I can't seem to tab into the list of application icon+names.

STEPS TO REPRODUCE
0. (These steps assume you haven't set an application to open empty document files.)
1. Create an empty file, save it as "test"
2. In Dolphin navigate to this file and double-click it.
3. The "Choose Application — Portal" window that appears, try to use the keyboard to choose an application to open "test" from the list.

OBSERVED RESULT
You can't tab into the list of applications, so you can't choose one.

EXPECTED RESULT
The usual keyboard navigation through a list of name+icon sets.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 
KDE Plasma Version: 5.27.2
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8 on Wayland

ADDITIONAL INFORMATION
I can't figure out how to bring up the Gnome equivalent app chooser to see if it has the same problem.

As a workaround, if you type enough in the filter field to filter the list of applications down to one, it gets a selection rectangle and you can press [Enter] to launch it.