A locale's UI language includes the script, e.g. the QLocale::uiLanguage
list for the Australian locale en_AU is {"en_Latn_AU", "en_AU", "en"}.
The old code iterated over each language in the outer loop, and for each
language tried several times, removing a segment from the back with each
try in the inner loop. The de-facto search order was then
en_Latn_AU
en_latn_au
en_Latn
en_latn
en
en_AU
en_au
en
Usually, translation files are provided for country_Territory, i.e.
en_AU. But if an en file (for a generic English translation) was also
present, then en_AU was never tried.
Fix this by breaking the logic into two loops: first, create a list of
candidates by removing segments from each UI Language. Then sort that
list of candidates so that entries with more segments come first. The
search order is now:
en_Latn_AU
en_latn_au
en_Latn
en_latn
en_AU
en_au
en
This way, en_AU gets loaded correctly, before en is tried.
Adjust the test, which was essentially duplicating the logic from
QTranslator to generate files. This only tested that two identical loops
result in the same thing. Instead of using the system locale, make the
test data-driven, and explicitly try en_US and en_AU, with candidate
files generated based on a hardcoded list for each data row.
Pick-to: 6.7 6.5
Fixes: QTBUG-124898
Change-Id: I6bdcff289d2843e61c9053c116e955b79e09e95a
Reviewed-by: Mate Barany <mate.barany@qt.io>
(cherry picked from commit 9a11273b745a30cebb5cd648c89eb224e9704492)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
8352306cdc