author Zibi Braniecki <>
Thu, 14 Sep 2017 15:21:33 -0700
changeset 424146 48109fce6741a2448a9d71f48deccbd72f732003
parent 40458 1584ba8c1b86f9c4de5ccda5241cef36e80f042c
permissions -rw-r--r--
Bug 1400006 - Extend language negotiation in LocaleService to support looking for the best likelySubtag for the locale with region stripped. r=Pike, a=lizzard Add additional logic to our language negotation to do apply likelySubtags when a direct match is not available. Currently, if the user specifies the locale with region, and we do not have a direct for that region, we pick all locales for the same language and other regions in no order. The example of where it returns suboptimal results: 1) Requested locale "en-CA" 2) Available locales ["en-ZA", "en-GB", "en-US"] 3) Negotiated locales ["en-ZA", "en-GB", "en-US"] This would not happen, if the user requested a generic "de", "en" etc.: 1) Requested locale "en" 2) Available locales ["en-ZA", "en-GB", "en-US"] 3) Negotiated locales ["en-US", "en-ZA", "en-GB"] because after not finding a direct match, we would use likelySubtags to extend "en" to "en-Latn-US" and then find the priority match in "en-US". This patch extends this logic to "en-US" or "de-LU" by adding a step which strips the region tag and then applies likelySubtag on the result. This means that in absence of direct match the following fallbacks would happen: "de-LU" -> "de-DE" "es-CL" -> "es-ES" "en-CA" -> "en-US" This does not affect languages that use multiple scripts, so ar, sr and zh are not affected. MozReview-Commit-ID: BR1WrgXSf6a

Please see the file toolkit/content/license.html for the copyright licensing
conditions attached to this codebase, including copies of the licenses

You are not granted rights or licenses to the trademarks of the
Mozilla Foundation or any party, including without limitation the
Firefox name or logo.

For more information, see: