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Firefox asking to be made the default browser again and again


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)

update-alternatives --display x-www-browser
update-alternatives --display gnome-www-browser

should both show firefox for you. If not

update-alternatives --config <entry>

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)

xdg-settings get default-web-browser

that you get firefox.desktop. If not run

xdg-settings check default-web-browser firefox.desktop

If you are running Gnome, check

xdg-settings get default-url-scheme-handler http

and the same for https.



sensible-editor ~/.config/mimeapps.list

and remove all entries that contain something like userapp-Firefox-<random>.desktop.


find ~/.local/share/applications -iname "userapp-firefox*.desktop"

and delete these files or move them away.


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?

Firefox opens directories in RawTherapee ... or a tale of colliding assumptions


After installing RawTherapee, a raw photo to jpg image converter, on my Kubuntu 13.04 desktop, Mozilla Firefox started to open the Downloads directory in ... RawTherapee. Gosh. Now that's what you'd want to browse a downloads folder with.

Update-alternatives did not help as RawTherapee is not managed by the Debian alternatives system. Hm, xdg-open still works as intended and opens dolphin.

Asking Google turns up many not working solution proposals. Hm.

Firefox: Context menu (right click) -> Open Containing Folder

But, searching the collective memory is not completely useless. There is a solved bug report on the RawTherapee bug tracker that explains the issue. The .desktop file RawTherapee installs contains inode/directory as a supported mime type. Well, that's technically correct but makes no sense in the way mime associations are used. Thankfully the bug reporter was able to convince the developer of this and get this fixed for future RawTherapee releases.

So option 1: edit /usr/share/applications/rawtherapee.desktop and remove the inode/directory entry from the MimeType=-line. Then regenerate the various mimetype caches.

This still bears the question why Firefox does not use the inode/directory entry from dolphin.desktop. Also, the next update from Debian/Ubuntu will probably overwrite the fixed rawtherapee.desktop file again as the patch from the Rawtherapee developer will only be included on new releases (and these may or may not be backported to Debian/Ubuntu). So you'd need to copy that fixed rawtherapee.desktop file to ~/.local/share/applications/ or the like.

Option 2: find out what the real issue is...

Continue reading "Firefox opens directories in RawTherapee ... or a tale of colliding assumptions"