1 files changed, 27 insertions, 23 deletions

diff --git a/src/corelib/text/qlocale.cpp b/src/corelib/text/qlocale.cpp
index 67b06f42f4..6cf0488f83 100644
--- a/src/corelib/text/qlocale.cpp
+++ b/src/corelib/text/qlocale.cpp
@@ -337,22 +337,6 @@ QByteArray QLocalePrivate::bcp47Name(char separator) const
     return localeId.withLikelySubtagsRemoved().name(separator);
 }
 
-/*!
-  \internal
- */
-QByteArray QLocalePrivate::rawName(char separator) const
-{
-    QByteArrayList parts;
-    if (m_data->m_language_id != QLocale::AnyLanguage)
-        parts.append(languageCode().latin1());
-    if (m_data->m_script_id != QLocale::AnyScript)
-        parts.append(scriptCode().latin1());
-    if (m_data->m_country_id != QLocale::AnyCountry)
-        parts.append(countryCode().latin1());
-
-    return parts.join(separator);
-}
-
 static const QLocaleData *findLocaleDataById(const QLocaleId &localeId)
 {
     const uint idx = locale_index[localeId.language_id];
@@ -4542,6 +4526,31 @@ QStringList QLocale::uiLanguages() const
         }
         if (locales.isEmpty())
             locales.append(systemLocale()->fallbackUiLocale());
+        // If the system locale (isn't C and) didn't include itself in the list,
+        // or as fallback, presume to know better than it and put its name
+        // first. (Known issue, QTBUG-104930, on some macOS versions when in
+        // locale en_DE.) Our translation system might have a translation for a
+        // locale the platform doesn't believe in.
+        const QString name = bcp47Name();
+        if (!name.isEmpty() && language() != C && !uiLanguages.contains(name)) {
+            // That uses contains(name) as a cheap pre-test, but there may be an
+            // entry that matches this on purging likely subtags.
+            QLocaleId mine =
+                { d->m_data->m_language_id, d->m_data->m_script_id, d->m_data->m_country_id };
+            mine = mine.withLikelySubtagsRemoved();
+            const auto isMine = [mine](const QString &entry) {
+                QLocale::Language lang;
+                QLocale::Script script;
+                QLocale::Country cntry;
+                QLocalePrivate::getLangAndCountry(entry, lang, script, cntry);
+                QLocaleId id = { ushort(lang), ushort(script), ushort(cntry) };
+                return id.withLikelySubtagsRemoved() == mine;
+            };
+            if (std::none_of(uiLanguages.constBegin(), uiLanguages.constEnd(), isMine)) {
+                locales.prepend(*this);
+                uiLanguages.prepend(name);
+            }
+        }
     } else
 #endif
     {
@@ -4554,13 +4563,8 @@ QStringList QLocale::uiLanguages() const
         if (i < uiLanguages.size()) {
             // Adding likely-adjusted forms to system locale's list.
             // Name the locale is derived from:
-            const QString &name = uiLanguages.at(i);
-            prior = name.toLatin1();
-            // Don't try to likely-adjust if construction's likely-adjustments
-            // were so drastic the result doesn't match the prior name:
-            if (locale.name() != name && locale.d->rawName() != prior)
-                continue;
-            // Insert just after prior:
+            prior = uiLanguages.at(i).toLatin1();
+            // Insert just after the entry we're supplementing:
             j = i + 1;
         } else {
             // Plain locale, not system locale; just append.