Sometimes tiny things make my day at 9am already.
That spammer got frustrated because none of his bots would get comments pasted to my blog:
Greetings to Cambodia.
BTW: Mikrotik RouterOS 6.41, CVE-2018-7445. RCE unpatched for 9+ months.
Firefox on Linux can develop the habit to (rather randomly) ask again and again to be made the default browser. E.g. when started from Thunderbird by clicking a link it asks but when starting from a shell all is fine.
The reason to this is often two (or more) .desktop entries competing with each other.
So, walkthrough: (GOTO 10 in case you are sure to have all the basics right)
should both show firefox for you. If not
the entry to fix the preference on /usr/bin/firefox.
Check (where available)
that the "Internet Browser" is "Firefox".
Check (where available)
that anything containing "html" points to Firefox (or is left at a non-user set default).
Check (where available)
that you get firefox.desktop. If not run
If you are running Gnome, check
and the same for https.
Run
and remove all entries that contain something like userapp-Firefox-<random>.desktop.
Run
and delete these files or move them away.
Done.
Once you have it working again consider disabling the option for Firefox to check whether it is the default browser. Because it will otherwise create those pesky userapp-Firefox-<random>.desktop files again.
Configuring Linux is easy, innit?