bug 256257: Font settings for western encoding apply when 'x-*' langGroup is specified (especially problematic in mail)

intl/locale/src/langGroups.properties

@@ -189,20 +189,21 @@ zu=x-western
 #
 #==============================
 #
-# x-western
+# mapping mozilla's internal x-* to themselves (see bug 256257)
-# x-central-euro
+x-western=x-western
-# x-cyrillic
+x-central-euro=x-central-euro
+x-cyrillic=x-cyrillic
 # el
 # tr
 # he
 # ar
-# x-baltic
+x-baltic=x-baltic
 # th
 # ja
 # zh-CN
 # ko
 # zh-TW
-# x-tamil
+x-tamil=x-tamil
-# x-devanagari
+x-devanagari=x-devanagari
-# x-unicode
+x-unicode=x-unicode
-# x-user-def
+x-user-def=x-user-def