I went to about:config. intl.accept_language is not overridden and is correctly set to: "fr, fr-fr, en-us, en"
If I override the option with the same string and a whitespace at the end, the Accept-Language HTTP field is correct.
If I reset the option back to "fr, fr-fr, en-us, en", the correct Accept-Language is still sent to the server. But if I restart Firefox the bug is back.
I went to about:config. intl.accept_ language is not overridden and is correctly set to: "fr, fr-fr, en-us, en"
If I override the option with the same string and a whitespace at the end, the Accept-Language HTTP field is correct.
If I reset the option back to "fr, fr-fr, en-us, en", the correct Accept-Language is still sent to the server. But if I restart Firefox the bug is back.