Use QLocaleId in place of language, script, country triples

Pass a single argument in place of three; and (prepare to) replace
QLocalePrivate::getLangAndCountry(), taking three out parameters, with
QLocaleId::fromName(). Removal of getLangAndCountry() must wait for
removal of linguist's use of it in qttools, which has to wait for this
change to land in qtbase. In the process, change findLocaleIndex()'s
return to int.

Change-Id: I9f5c44c41f2dd1598c53ed5ccb0abddc6b17d21f
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

4 files changed, 39 insertions, 54 deletions

diff --git a/src/corelib/text/qlocale.cpp b/src/corelib/text/qlocale.cpp
index 5375f71153..d58562e587 100644
--- a/src/corelib/text/qlocale.cpp
+++ b/src/corelib/text/qlocale.cpp
@@ -369,10 +369,9 @@ static int findLocaleIndexById(const QLocaleId &localeId)
     return -1;
 }
 
-uint QLocaleData::findLocaleIndex(QLocale::Language language, QLocale::Script script,
-                                  QLocale::Country country)
+int QLocaleData::findLocaleIndex(QLocaleId lid)
 {
-    QLocaleId localeId { language, script, country };
+    QLocaleId localeId = lid;
     QLocaleId likelyId = localeId.withLikelySubtagsAdded();
     const ushort fallback = likelyId.language_id;
 
@@ -396,9 +395,8 @@ uint QLocaleData::findLocaleIndex(QLocale::Language language, QLocale::Script sc
     CheckCandidate(localeId);
 
     // No match; try again with likely country for language_script
-    if (country != QLocale::AnyCountry
-        && (language != QLocale::AnyLanguage || script != QLocale::AnyScript)) {
-        localeId = QLocaleId { language, script, QLocale::AnyCountry };
+    if (lid.country_id && (lid.language_id || lid.script_id)) {
+        localeId.country_id = 0;
         likelyId = localeId.withLikelySubtagsAdded();
         CheckCandidate(likelyId);
 
@@ -407,9 +405,8 @@ uint QLocaleData::findLocaleIndex(QLocale::Language language, QLocale::Script sc
     }
 
     // No match; try again with likely script for language_region
-    if (script != QLocale::AnyScript
-        && (language != QLocale::AnyLanguage || country != QLocale::AnyCountry)) {
-        localeId = QLocaleId { language, QLocale::AnyScript, country };
+    if (lid.script_id && (lid.language_id || lid.country_id)) {
+        localeId = QLocaleId { lid.language_id, 0, lid.country_id };
         likelyId = localeId.withLikelySubtagsAdded();
         CheckCandidate(likelyId);
 
@@ -499,34 +496,28 @@ bool qt_splitLocaleName(const QString &name, QString &lang, QString &script, QSt
     return lang.length() == 2 || lang.length() == 3;
 }
 
+// TODO: kill this !  Still in use by qttools, patch submitted (2020 October).
 void QLocalePrivate::getLangAndCountry(const QString &name, QLocale::Language &lang,
                                        QLocale::Script &script, QLocale::Country &cntry)
 {
-    lang = QLocale::C;
-    script = QLocale::AnyScript;
-    cntry = QLocale::AnyCountry;
-
-    QString lang_code;
-    QString script_code;
-    QString cntry_code;
-    if (!qt_splitLocaleName(name, lang_code, script_code, cntry_code))
-        return;
-
-    lang = QLocalePrivate::codeToLanguage(lang_code);
-    if (lang == QLocale::C)
-        return;
-    script = QLocalePrivate::codeToScript(script_code);
-    cntry = QLocalePrivate::codeToCountry(cntry_code);
+    const auto id = QLocaleId::fromName(name);
+    lang = QLocale::Language(id.language_id);
+    script = QLocale::Script(id.script_id);
+    cntry = QLocale::Country(id.country_id);
 }
 
-static uint findLocaleIndex(const QString &name)
+QLocaleId QLocaleId::fromName(const QString &name)
 {
-    QLocale::Language lang;
-    QLocale::Script script;
-    QLocale::Country cntry;
-    QLocalePrivate::getLangAndCountry(name, lang, script, cntry);
+    QString lang;
+    QString script;
+    QString cntry;
+    if (!qt_splitLocaleName(name, lang, script, cntry))
+        return { QLocale::C, 0, 0 };
 
-    return QLocaleData::findLocaleIndex(lang, script, cntry);
+    QLocale::Language langId = QLocalePrivate::codeToLanguage(lang);
+    if (langId == QLocale::C)
+        return QLocaleId { langId, 0, 0 };
+    return { langId, QLocalePrivate::codeToScript(script), QLocalePrivate::codeToCountry(cntry) };
 }
 
 QString qt_readEscapedFormatString(QStringView format, int *idx)
@@ -744,7 +735,8 @@ static QLocalePrivate *localePrivateByName(const QString &name)
 {
     if (name == QLatin1String("C"))
         return c_private();
-    const uint index = findLocaleIndex(name);
+    const int index = QLocaleData::findLocaleIndex(QLocaleId::fromName(name));
+    Q_ASSERT(index >= 0 && size_t(index) < std::size(locale_data) - 1);
     return QLocalePrivate::create(locale_data + index, index,
                                   locale_data[index].m_language_id == QLocale::C
                                   ? QLocale::OmitGroupSeparator : QLocale::DefaultNumberOptions);
@@ -756,7 +748,8 @@ static QLocalePrivate *findLocalePrivate(QLocale::Language language, QLocale::Sc
     if (language == QLocale::C)
         return c_private();
 
-    uint index = QLocaleData::findLocaleIndex(language, script, country);
+    int index = QLocaleData::findLocaleIndex(QLocaleId { language, script, country });
+    Q_ASSERT(index >= 0 && size_t(index) < std::size(locale_data) - 1);
     const QLocaleData *data = locale_data + index;
 
     QLocale::NumberOptions numberOptions = QLocale::DefaultNumberOptions;
diff --git a/src/corelib/text/qlocale_p.h b/src/corelib/text/qlocale_p.h
index 756e1afc93..8be0eeda92 100644
--- a/src/corelib/text/qlocale_p.h
+++ b/src/corelib/text/qlocale_p.h
@@ -148,6 +148,7 @@ namespace QIcu {
 
 struct QLocaleId
 {
+    static QLocaleId fromName(const QString &name);
     inline bool operator==(QLocaleId other) const
     { return language_id == other.language_id && script_id == other.script_id && country_id == other.country_id; }
     inline bool operator!=(QLocaleId other) const
@@ -188,9 +189,7 @@ struct QLocaleData
 public:
     // Having an index for each locale enables us to have diverse sources of
     // data, e.g. calendar locales, as well as the main CLDR-derived data.
-    static uint findLocaleIndex(QLocale::Language language,
-                                QLocale::Script script,
-                                QLocale::Country country);
+    static int findLocaleIndex(QLocaleId localeId);
     static const QLocaleData *c();
 
     enum DoubleForm {
diff --git a/src/corelib/text/qlocale_unix.cpp b/src/corelib/text/qlocale_unix.cpp
index 51b23f1559..b1edd0dd3c 100644
--- a/src/corelib/text/qlocale_unix.cpp
+++ b/src/corelib/text/qlocale_unix.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2020 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtCore module of the Qt Toolkit.
@@ -128,14 +128,9 @@ static bool contradicts(const QString &maybe, const QString &known)
       Belarusian.  There are many more such prefixings between two- and
       three-letter codes.)
      */
-    QLocale::Language langm, langk;
-    QLocale::Script scriptm, scriptk;
-    QLocale::Country landm, landk;
-    QLocalePrivate::getLangAndCountry(maybe, langm, scriptm, landm);
-    QLocalePrivate::getLangAndCountry(known, langk, scriptk, landk);
-    return (langm != QLocale::AnyLanguage && langm != langk)
-        || (scriptm != QLocale::AnyScript && scriptm != scriptk)
-        || (landm != QLocale::AnyCountry && landm != landk);
+    QLocaleId knownId = QLocaleId::fromName(known);
+    QLocaleId maybeId = QLocaleId::fromName(maybe);
+    return !(maybeId.acceptLanguage(knownId.language_id) && maybeId.acceptScriptCountry(knownId));
 }
 
 QLocale QSystemLocale::fallbackUiLocale() const
@@ -270,10 +265,12 @@ QVariant QSystemLocale::query(QueryType type, QVariant in) const
         else
             lst = languages.split(QLatin1Char(':'));
 
+        // Inadequate for various cases of a language that's written in more
+        // than one script in the same country, e.g. Sindhi in India.
+        // However, can clients of the UILanguage query cope if we include script ?
         for (int i = 0; i < lst.size(); ++i) {
-            const QString &name = lst.at(i);
             QString lang, script, cntry;
-            if (qt_splitLocaleName(name, lang, script, cntry)) {
+            if (qt_splitLocaleName(lst.at(i), lang, script, cntry)) {
                 if (!cntry.length())
                     d->uiLanguages.append(lang);
                 else
diff --git a/src/corelib/text/qlocale_win.cpp b/src/corelib/text/qlocale_win.cpp
index a88f3e5227..1e32e6721f 100644
--- a/src/corelib/text/qlocale_win.cpp
+++ b/src/corelib/text/qlocale_win.cpp
@@ -758,16 +758,12 @@ QVariant QSystemLocale::query(QueryType type, QVariant in) const
     case LanguageId:
     case ScriptId:
     case CountryId: {
-        QString locale = QString::fromLatin1(getWinLocaleName());
-        QLocale::Language lang;
-        QLocale::Script script;
-        QLocale::Country cntry;
-        QLocalePrivate::getLangAndCountry(locale, lang, script, cntry);
+        QLocaleId lid = QLocaleId::fromName(QString::fromLatin1(getWinLocaleName()));
         if (type == LanguageId)
-            return lang;
+            return lid.language_id;
         if (type == ScriptId)
-            return script == QLocale::AnyScript ? fallbackUiLocale().script() : script;
-        return cntry == QLocale::AnyCountry ? fallbackUiLocale().country() : cntry;
+            return lid.script_id ? lid.script_id : fallbackUiLocale().script();
+        return lid.country_id ? lid.country_id : fallbackUiLocale().country();
     }
     case MeasurementSystem:
         return d->measurementSystem();