Implement language fallback logic for localize_deployment

When querying system locale it does return both language and country,
so sometimes users want to have both in their .ts file names
(e.g. myapp_zh_CN.ts). This is bit problematic in Symbian, where
there are separate language codes for only very few language +
country combinations. Until now, the unsupported combinations were
simply dropped from deployment localization.

More proper way to handle these unknown language + country combinations
is to fall back to using the plain language code for them instead of
dropping them altogether. This is somewhat analogous to how
QTranslator::load() loads .ts files if it can't find the file for
specified language + country combination.

E.g. User defines:

TRANSLATIONS += myapp_zh_CN.ts myapp_zh_HK.ts myapp_zh_TW.ts

There are separate Symbian language codes for HongKong Chinese
(zh_HK = 30) and Taiwanese Chinese (zh_TW = 29), but rest of the world
is expected to use just Chinese (zh = 31). This means "zh_CN" mapping
is not provided as it would be same as plain "zh".

With this fix, qmake will now automatically generate a fallback
mapping from "zh_CN" to "31" for deployment localization purposes, and
is able to read application captions and pkg names from myapp_zh_CN.ts.

If there are multiple TRANSLATIONS defined that would result in same
Symbian language code, only the first one is used.

Task-number: QTBUG-17927
Reviewed-by: Oswald Buddenhagen

1 files changed, 9 insertions, 0 deletions

diff --git a/mkspecs/features/symbian/localize_deployment.prf b/mkspecs/features/symbian/localize_deployment.prf
index 26a254b..185c713 100644
--- a/mkspecs/features/symbian/localize_deployment.prf
+++ b/mkspecs/features/symbian/localize_deployment.prf
@@ -101,6 +101,15 @@ isEmpty(SYMBIAN_MATCHED_LANGUAGES) {
     matchSymbianLanguages()
 }
 
+# If there are translations that do not have Symbian language code defined for that exact
+# language + country combination, but have Symbian language code defined for just the language,
+# map the language + country combination to the same value as the plain language.
+for(language, SYMBIAN_UNMAPPED_LANGUAGES) {
+    languageVar = SYMBIAN_LANG.$${language}
+    fallbackLanguageVar = SYMBIAN_LANG.$$eval(SYMBIAN_LANGUAGE_FALLBACK.$$language)
+    $$languageVar = $$eval($$fallbackLanguageVar)
+}
+
 !isEmpty(SYMBIAN_MATCHED_TRANSLATIONS) {
     # Generate dependencies to .ts files for pkg files
     template_pkg_target.depends += $$SYMBIAN_MATCHED_TRANSLATIONS