Add Latgalian translation

Closes #12415

src/base/unicodestrings.h

@@ -74,6 +74,7 @@ const char C_LOCALE_INDONESIAN[] = "Bahasa Indonesia";
 const char C_LOCALE_ITALIAN[] = "Italiano";
 const char C_LOCALE_JAPANESE[] = "日本語";
 const char C_LOCALE_KOREAN[] = "한글";
+const char C_LOCALE_LATGALIAN[] = "latgalīšu volūda";
 const char C_LOCALE_LATVIAN[] = "latviešu valoda";
 const char C_LOCALE_LITHUANIAN[] = "Lietuvių";
 const char C_LOCALE_MALAY[] = "بهاس ملايو";

src/gui/optionsdialog.cpp

@@ -575,6 +575,10 @@ void OptionsDialog::initializeLanguageCombo()
             // QLocale doesn't work with that locale. Esperanto isn't a "real" language.
             languageName = QString::fromUtf8(C_LOCALE_ESPERANTO);
         }
+        else if (localeStr.startsWith("ltg", Qt::CaseInsensitive)) {
+            // QLocale doesn't work with that locale.
+            languageName = QString::fromUtf8(C_LOCALE_LATGALIAN);
+        }
         else {
             QLocale locale(localeStr);
             languageName = languageToLocalizedString(locale);
@@ -1549,6 +1553,9 @@ void OptionsDialog::setLocale(const QString &localeStr)
     if (localeStr.startsWith("eo", Qt::CaseInsensitive)) {
         name = "eo";
     }
+    else if (localeStr.startsWith("ltg", Qt::CaseInsensitive)) {
+        name = "ltg";
+    }
     else {
         QLocale locale(localeStr);
         if (locale.language() == QLocale::Uzbek)

src/lang/lang.qrc

@@ -29,6 +29,7 @@
         <file>qbittorrent_ka.qm</file>
         <file>qbittorrent_ko.qm</file>
         <file>qbittorrent_lt.qm</file>
+        <file>qbittorrent_ltg.qm</file>
         <file>qbittorrent_lv_LV.qm</file>
         <file>qbittorrent_ms_MY.qm</file>
         <file>qbittorrent_nb.qm</file>

src/webui/www/private/views/preferences.html

@@ -668,6 +668,7 @@
             <option value="pl_PL">Polski</option>
             <option value="lv_LV">latviešu valoda</option>
             <option value="lt_LT">Lietuvių</option>
+            <option value="ltg">latgalīšu volūda</option>
             <option value="ms_MY">بهاس ملايو</option>
             <option value="cs_CZ">Čeština</option>
             <option value="sk_SK">Slovenčina</option>

src/webui/www/translations/webui_translations.qrc

@@ -29,6 +29,7 @@
         <file>webui_ka.qm</file>
         <file>webui_ko.qm</file>
         <file>webui_lt.qm</file>
+        <file>webui_ltg.qm</file>
         <file>webui_lv_LV.qm</file>
         <file>webui_ms_MY.qm</file>
         <file>webui_nb.qm</file>