[Bug-gnuzilla] Switching interface language in about:config crashed IceCat

[David Englund]

1) Installing http://ftp.gnu.org/gnu/gnuzilla/31.5.0-gnu2/langpacks/icecat-31.5.0.sv-SE.langpack.xpi

2) Modified about:config by follow the instructions in https://support.mozilla.org/en-US/questions/1018686 used to "switch between different interface languages":
* `intl.locale.matchOS` was set to `false`
* `general.useragent.locale` was set to `sv-SE`, nothing I've added, its there as I installed the language pack in step 1 above.
* Restart Firefox for the change to take effect.

This cause IceCat to pop-up endless of message boxes. I had no chance to see any text in these boxes or select anything (pressing enter or right-key enter) did not help.

Rebooting Trisquel 7.0 LTE out of stress of seeing nearly 100 pop-up dialogs, did not help either. However, modifying `user_pref("intl.locale.matchOS", false);` in /.mozilla/icecat/t9roh80p.default/prefs.js made IceCat behave normal again, no pop-ups at all.


Please file this bug to Firefox ESR if its not IceCat related. Or should I install Firefox ESR and try to reproduce this bug?