Firefox opens KML file in neverending loop if associated with "System Handler"

[Jaromir Obr]

Found when trying open a KML export file from Google Timeline.
It can be reproduced even with an empty KML file.

Steps:
* Create an empty file "test.kml" (run "$ touch test.kml")
* Open the application "Files"
* Right click on the test.kml and open it with Firefox
* Open with "System Handler" and check the option "Do this automatically for files like this from now on" (see "Screenshot from 2022-06-05 11-13-23.png")

Expected result:
* No infinite opening

Actual result:
* Firefox starts opening the file again and again (see "Screenshot from 2022-06-05 11-04-35.png")

Used SW:
* Ubuntu 22.04 LTS
* Firefox 101.0
* Files 42.1.1

[Olivier Tilloy (osomon)]

I can observe the problem in a fully up-to-date Ubuntu 22.04 VM.

I'm not sure what should be the expected behaviour though. Do you expect firefox to open/render a KML file in any useful way?

[Jaromir Obr (jaromir-obr)]

I would expect that Firefox should show the dialog "What to do with file?" again if OS is not able to open the file regardless the option "Do this automatically from now" is ticked.
I guess Firefox nor OS cannot handle KML file itself. However the state "New tab is open again and again automatically" shouldn't occur because it could exhaust memory in worst case and it's also bad use experience to see neverending opening of new tabs.

[Launchpad Janitor (janitor)]

[Expired for firefox (Ubuntu) because there has been no activity for 60 days.]

[Olivier Tilloy (osomon)]

Sorry for the lack of feedback, this is clearly a valid issue that should be looked into. Would you mind filing an upstream bug report at https://bugzilla.mozilla.org/enter_bug.cgi?product=Firefox and sharing the link to it here?