1 files changed, 136 insertions, 29 deletions

diff --git a/src/corelib/tools/qlocale.cpp b/src/corelib/tools/qlocale.cpp
index 42cb3eda18..2f0e4970b0 100644
--- a/src/corelib/tools/qlocale.cpp
+++ b/src/corelib/tools/qlocale.cpp
@@ -208,17 +208,94 @@ QString QLocalePrivate::countryCode() const
     return code;
 }
 
-QString QLocalePrivate::bcp47Name() const
+// http://www.unicode.org/reports/tr35/#Likely_Subtags
+static bool addLikelySubtags(QLocaleId &localeId)
+{
+    // ### optimize with bsearch
+    const int likely_subtags_count = sizeof(likely_subtags) / sizeof(likely_subtags[0]);
+    const QLocaleId *p = likely_subtags;
+    const QLocaleId *const e = p + likely_subtags_count;
+    for ( ; p < e; p += 2) {
+        if (localeId == p[0]) {
+            localeId = p[1];
+            return true;
+        }
+    }
+    return false;
+}
+
+QLocaleId QLocaleId::withLikelySubtagsAdded() const
 {
-    if (m_data->m_language_id == QLocale::AnyLanguage)
+    // language_script_region
+    if (language_id || script_id || country_id) {
+        QLocaleId id = QLocaleId::fromIds(language_id, script_id, country_id);
+        if (addLikelySubtags(id))
+            return id;
+    }
+    // language_script
+    if (country_id) {
+        QLocaleId id = QLocaleId::fromIds(language_id, script_id, 0);
+        if (addLikelySubtags(id)) {
+            id.country_id = country_id;
+            return id;
+        }
+    }
+    // language_region
+    if (script_id) {
+        QLocaleId id = QLocaleId::fromIds(language_id, 0, country_id);
+        if (addLikelySubtags(id)) {
+            id.script_id = script_id;
+            return id;
+        }
+    }
+    // language
+    if (script_id && country_id) {
+        QLocaleId id = QLocaleId::fromIds(language_id, 0, 0);
+        if (addLikelySubtags(id)) {
+            id.script_id = script_id;
+            id.country_id = country_id;
+            return id;
+        }
+    }
+    return *this;
+}
+
+QLocaleId QLocaleId::withLikelySubtagsRemoved() const
+{
+    QLocaleId max = withLikelySubtagsAdded();
+    // language
+    {
+        QLocaleId id = QLocaleId::fromIds(language_id, 0, 0);
+        if (id.withLikelySubtagsAdded() == max)
+            return id;
+    }
+    // language_region
+    if (country_id) {
+        QLocaleId id = QLocaleId::fromIds(language_id, 0, country_id);
+        if (id.withLikelySubtagsAdded() == max)
+            return id;
+    }
+    // language_script
+    if (script_id) {
+        QLocaleId id = QLocaleId::fromIds(language_id, script_id, 0);
+        if (id.withLikelySubtagsAdded() == max)
+            return id;
+    }
+    return max;
+}
+
+QString QLocaleId::bcp47Name() const
+{
+    if (language_id == QLocale::AnyLanguage)
         return QString();
-    if (m_data->m_language_id == QLocale::C)
+    if (language_id == QLocale::C)
         return QStringLiteral("C");
-    const unsigned char *lang = language_code_list + 3*(uint(m_data->m_language_id));
+
+    const unsigned char *lang = language_code_list + 3*uint(language_id);
     const unsigned char *script =
-            (m_data->m_script_id != QLocale::AnyScript ? script_code_list + 4*(uint(m_data->m_script_id)) : 0);
+            (script_id != QLocale::AnyScript ? script_code_list + 4*uint(script_id) : 0);
     const unsigned char *country =
-            (m_data->m_country_id != QLocale::AnyCountry  ? country_code_list + 3*(uint(m_data->m_country_id)) : 0);
+            (country_id != QLocale::AnyCountry  ? country_code_list + 3*uint(country_id) : 0);
     char len = (lang[2] != 0 ? 3 : 2) + (script ? 4+1 : 0) + (country ? (country[2] != 0 ? 3 : 2)+1 : 0);
     QString name(len, Qt::Uninitialized);
     QChar *uc = name.data();
@@ -243,42 +320,59 @@ QString QLocalePrivate::bcp47Name() const
     return name;
 }
 
+QString QLocalePrivate::bcp47Name() const
+{
+    if (m_data->m_language_id == QLocale::AnyLanguage)
+        return QString();
+    if (m_data->m_language_id == QLocale::C)
+        return QStringLiteral("C");
+
+    QLocaleId localeId = QLocaleId::fromIds(m_data->m_language_id, m_data->m_script_id, m_data->m_country_id);
+    return localeId.withLikelySubtagsRemoved().bcp47Name();
+}
+
 const QLocaleData *QLocaleData::findLocaleData(QLocale::Language language, QLocale::Script script, QLocale::Country country)
 {
-    const unsigned language_id = language;
-    const unsigned script_id = script;
-    const unsigned country_id = country;
+    QLocaleId localeId = QLocaleId::fromIds(language, script, country);
+    localeId = localeId.withLikelySubtagsAdded();
 
-    uint idx = locale_index[language_id];
+    uint idx = locale_index[localeId.language_id];
 
     const QLocaleData *data = locale_data + idx;
 
     if (idx == 0) // default language has no associated country
         return data;
 
-    if (script == QLocale::AnyScript && country == QLocale::AnyCountry)
-        return data;
+    Q_ASSERT(data->m_language_id == localeId.language_id);
 
-    Q_ASSERT(data->m_language_id == language_id);
-
-    if (country == QLocale::AnyCountry) {
-        while (data->m_language_id == language_id && data->m_script_id != script_id)
+    if (localeId.script_id != QLocale::AnyScript && localeId.country_id != QLocale::AnyCountry) {
+        // both script and country are explicitly specified
+        do {
+            if (data->m_script_id == localeId.script_id && data->m_country_id == localeId.country_id)
+                return data;
             ++data;
-        if (data->m_language_id == language_id && data->m_script_id == script_id)
-            return data;
-    } else if (script == QLocale::AnyScript) {
-        while (data->m_language_id == language_id) {
-            if (data->m_script_id == script_id && data->m_country_id == country_id)
+        } while (data->m_language_id == localeId.language_id);
+
+        // no match; try again with default script
+        localeId.script_id = QLocale::AnyScript;
+        data = locale_data + idx;
+    }
+
+    if (localeId.script_id == QLocale::AnyScript && localeId.country_id == QLocale::AnyCountry)
+        return data;
+
+    if (localeId.script_id == QLocale::AnyScript) {
+        do {
+            if (data->m_country_id == localeId.country_id)
                 return data;
             ++data;
-        }
-    } else {
-        // both script and country are explicitly specified
-        while (data->m_language_id == language_id) {
-            if (data->m_script_id == script_id && data->m_country_id == country_id)
+        } while (data->m_language_id == localeId.language_id);
+    } else if (localeId.country_id == QLocale::AnyCountry) {
+        do {
+            if (data->m_script_id == localeId.script_id)
                 return data;
             ++data;
-        }
+        } while (data->m_language_id == localeId.language_id);
     }
 
     return locale_data + idx;
@@ -3227,7 +3321,7 @@ QString QLocale::toCurrencyString(double value, const QString &symbol) const
     \since 4.8
 
     Returns an ordered list of locale names for translation purposes in
-    preference order.
+    preference order (like "en", "en-US", "en-Latn-US").
 
     The return value represents locale names that the user expects to see the
     UI translation in.
@@ -3251,7 +3345,20 @@ QStringList QLocale::uiLanguages() const
         }
     }
 #endif
-    return QStringList(bcp47Name());
+    QLocaleId id = QLocaleId::fromIds(d->m_data->m_language_id, d->m_data->m_script_id, d->m_data->m_country_id);
+    const QLocaleId max = id.withLikelySubtagsAdded();
+    const QLocaleId min = max.withLikelySubtagsRemoved();
+
+    QStringList uiLanguages;
+    uiLanguages.append(min.bcp47Name());
+    if (id.script_id) {
+        id.script_id = 0;
+        if (id != min && id.withLikelySubtagsAdded() == max)
+            uiLanguages.append(id.bcp47Name());
+    }
+    if (max != min && max != id)
+        uiLanguages.append(max.bcp47Name());
+    return uiLanguages;
 }
 
 /*!