firefox-4.0-r3 lacks at least the following locales: zh-CN and zh-TW (Chinese) which is supported by the upstream: http://releases.mozilla.org/pub/mozilla.org/firefox/releases/4.0/linux-x86_64/xpi/ I think the list of the locales in the ebuild need a update. Reproducible: Always
Also confirmed in www-client/firefox-4.0.1. I notice that the languages listed in NOSHORTLANGS are not available. Is this a bug in the ebuild or intended?
It seems _some_ of the mirrors for Mozilla do not have those XPI files, and the list was retrieve from one of those mirrors. Anyway, at least this mirror works: http://ftp.osuosl.org/pub/mozilla.org/firefox/releases/4.0.1/linux-x86_64/xpi/
According to the scirpt/get_lang.sh from mozilla overlay, the LANG list of Firefox 4.0 is now updated to: LANGS="af ak ar ast be bg bn-BD bn-IN br bs ca cs cy da de el en en-GB en-US en-ZA eo es-AR es-CL es-ES es-MX et eu fa fi fr fy-NL ga-IE gd gl gu-IN he hi-IN hr hu hy-AM id is it ja kk kn ko ku lg lt lv mai mk ml mr nb-NO nl nn-NO nso or pa-IN pl pt-BR pt-PT rm ro ru si sk sl son sq sr sv-SE ta ta-LK te th tr uk vi zh-CN zh-TW zu" For those who can hold a local overlay, the above list should be helpful. Hope Mozilla team can help push the new list in.
This bug is still present in Firefox 5.0. One of the missing LINGUAS is pt-BR. However, I was able to intall manually the add-on from the following link: http://releases.mozilla.org/pub/mozilla.org/firefox/releases/5.0/linux-x86_64/xpi/pt-BR.xpi
Firefox 4.0 won't get any more updates, but I've updated the locales for 5.0, thanks for reporting! Closing as FIXED.