Translation not loaded because their name are over specified

[shenlebantongying]

Summary:

We should make translation filenames shorter but no shorter than necessary (and the format should follow bcp47)

• Delete country codes if unnecessary (e.g. ar_SA -> ar).
• Merge a few unnecessary variants (de_*, es_*...)
• Rename zh_CN to zh_Hans and zh_TW to zh_Hant.
• This works everywhere.

The problem is that QTranslator::load's algorithm, https://doc.qt.io/qt-6/qtranslator.html#load-1.

It will remove elements from the back of the lang code. If a translation file is over-specified and user have a different territory code, it won't load.

For example:

If user has system locale ar_QA (Arabic - Qatar), then the QTranslator will try (ar_QA, ar). The ar_SA that we have will be ignored because it is over-specified (Just ar is good.).

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Sample other projects:

• https://github.com/qt/qttranslations/tree/dev/translations
• https://github.com/qbittorrent/qBittorrent/tree/master/src/lang
• https://github.com/transmission/transmission/tree/main/po

Related doc:

• https://www.rfc-editor.org/rfc/pdfrfc/rfc5646.txt.pdf

Previous issue

• Some suspected language translations which I have not found with the file name as Language . #530

[shenlebantongying]

macOS

.

The QLocale::system().uiLanguages() is QList("zh-Hans-CA", "zh-CA", "en", "en-Latn-US", "en-US", "en-CA", "en-Latn-CA").

Linux/KDE and Windows

QLocale also returns a triplets. QLocale::system().uiLanguages() returns QList("zh-CN", "zh-Hans-CN", "zh").

.

https://learn.microsoft.com/en-us/globalization/locale/standard-locale-names