Revert: use the new form of QTranslator::load() for more flexibility

This reverts commit 427646b8d7c52e5b84240e07ffd391217ce3bfa8.
It seems that it should have been more correct, but we are still not
shipping English translations, and static QString find_translation()
in qtranslator.cpp will return any language which is in
QLocale::uiLanguages() for which the translation file is found.
That is a long list on OSX.

Reverting the patch means find_translation() is not called in
such cases.  This change can be re-done whenever we are more sure
that the attempt to find a translation will succeed in finding a
sensible one, or fall back to not translating, rather than choosing
a language that the user didn't intend.

Task-number: QTBUG-41977
Change-Id: I425946cc71cec96b4f38629eb2b7e80220c5236d
Reviewed-by: Jan Arve Sæther <jan-arve.saether@theqtcompany.com>

4 files changed, 13 insertions, 16 deletions

diff --git a/examples/quick/demos/photoviewer/main.cpp b/examples/quick/demos/photoviewer/main.cpp
index 1351f043f3..ca495242a4 100644
--- a/examples/quick/demos/photoviewer/main.cpp
+++ b/examples/quick/demos/photoviewer/main.cpp
@@ -40,9 +40,8 @@ int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
 
-    QLocale locale;
     QTranslator qtTranslator;
-    qtTranslator.load(locale, QLatin1String("qml"), QLatin1String("_"), QLatin1String(":/i18n"));
+    qtTranslator.load("qml_" + QLocale::system().name(), ":/i18n/");
     app.installTranslator(&qtTranslator);
 
     QQmlApplicationEngine engine;
diff --git a/src/qml/qml/qqmlapplicationengine.cpp b/src/qml/qml/qqmlapplicationengine.cpp
index 9ccaee7cd7..240c01233b 100644
--- a/src/qml/qml/qqmlapplicationengine.cpp
+++ b/src/qml/qml/qqmlapplicationengine.cpp
@@ -65,8 +65,7 @@ void QQmlApplicationEnginePrivate::init()
     q->connect(q, SIGNAL(quit()), QCoreApplication::instance(), SLOT(quit()));
 #ifndef QT_NO_TRANSLATION
     QTranslator* qtTranslator = new QTranslator;
-    QLocale locale;
-    if (qtTranslator->load(locale, QLatin1String("qt"), QLatin1String("_"), QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
+    if (qtTranslator->load(QLatin1String("qt_") + QLocale::system().name(), QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
         QCoreApplication::installTranslator(qtTranslator);
     translators << qtTranslator;
 #endif
@@ -83,8 +82,7 @@ void QQmlApplicationEnginePrivate::loadTranslations(const QUrl &rootFile)
     QFileInfo fi(rootFile.toLocalFile());
 
     QTranslator *translator = new QTranslator;
-    QLocale locale;
-    if (translator->load(locale, QLatin1String("qml"), QLatin1String("_"), fi.path() + QLatin1String("/i18n"))) {
+    if (translator->load(QLatin1String("qml_") + QLocale::system().name(), fi.path() + QLatin1String("/i18n"))) {
         QCoreApplication::installTranslator(translator);
         translators << translator;
     } else {
diff --git a/tools/qml/main.cpp b/tools/qml/main.cpp
index 7a08562a13..69ccd7a316 100644
--- a/tools/qml/main.cpp
+++ b/tools/qml/main.cpp
@@ -450,8 +450,10 @@ int main(int argc, char *argv[])
         verboseMode = false;
 
 #ifndef QT_NO_TRANSLATION
-    // qt_ translations are loaded by QQmlApplicationEngine
-    if (!translationFile.isEmpty()) { // Note: installed before QQmlApplicationEngine's automatic translation loading
+    //qt_ translations loaded by QQmlApplicationEngine
+    QString sysLocale = QLocale::system().name();
+
+    if (!translationFile.isEmpty()) { //Note: installed before QQmlApplicationEngine's automatic translation loading
         QTranslator translator;
 
         if (translator.load(translationFile)) {
diff --git a/tools/qmlscene/main.cpp b/tools/qmlscene/main.cpp
index 7c2fd9fc32..208226c8aa 100644
--- a/tools/qmlscene/main.cpp
+++ b/tools/qmlscene/main.cpp
@@ -307,8 +307,7 @@ static void displayFileDialog(Options *options)
 #ifndef QT_NO_TRANSLATION
 static void loadTranslationFile(QTranslator &translator, const QString& directory)
 {
-    QLocale locale;
-    translator.load(locale, QLatin1String("qml"), QLatin1String("_"), directory + QLatin1String("/i18n"));
+    translator.load(QLatin1String("qml_" )+QLocale::system().name(), directory + QLatin1String("/i18n"));
     QCoreApplication::installTranslator(&translator);
 }
 #endif
@@ -416,18 +415,17 @@ int main(int argc, char ** argv)
     app.setOrganizationDomain("qt-project.org");
 
 #ifndef QT_NO_TRANSLATION
-    QLocale locale;
+    QTranslator translator;
     QTranslator qtTranslator;
-    if (qtTranslator.load(locale, QLatin1String("qt"), QLatin1String("_"), QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
+    QString sysLocale = QLocale::system().name();
+    if (qtTranslator.load(QLatin1String("qt_") + sysLocale, QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
         app.installTranslator(&qtTranslator);
-
-    QTranslator translator;
-    if (translator.load(locale, QLatin1String("qmlscene"), QLatin1String("_"), QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
+    if (translator.load(QLatin1String("qmlscene_") + sysLocale, QLibraryInfo::location(QLibraryInfo::TranslationsPath)))
         app.installTranslator(&translator);
 
     QTranslator qmlTranslator;
     if (!options.translationFile.isEmpty()) {
-        if (qmlTranslator.load(locale, options.translationFile)) {
+        if (qmlTranslator.load(options.translationFile)) {
             app.installTranslator(&qmlTranslator);
         } else {
             qWarning() << "Could not load the translation file" << options.translationFile;