Fix normalization of app locales

Use the internal Chromium routine to get the app locale Chromium
expects.

Fixes: QTBUG-91715
Change-Id: I5042eb066cb6879ad69628959912f2841867b4e8
Reviewed-by: Michael Brüning <michael.bruning@qt.io>

4 files changed, 40 insertions, 11 deletions

diff --git a/src/core/content_browser_client_qt.cpp b/src/core/content_browser_client_qt.cpp
index e13ecd8d1..c2c78ff8b 100644
--- a/src/core/content_browser_client_qt.cpp
+++ b/src/core/content_browser_client_qt.cpp
@@ -471,7 +471,12 @@ std::unique_ptr<net::ClientCertStore> ContentBrowserClientQt::CreateClientCertSt
 
 std::string ContentBrowserClientQt::GetApplicationLocale()
 {
-    return WebEngineLibraryInfo::getApplicationLocale();
+    std::string bcp47Name = QLocale().bcp47Name().toStdString();
+    if (m_cachedQtLocale != bcp47Name) {
+        m_cachedQtLocale = bcp47Name;
+        m_appLocale = WebEngineLibraryInfo::getApplicationLocale();
+    }
+    return m_appLocale;
 }
 
 std::string ContentBrowserClientQt::GetAcceptLangs(content::BrowserContext *context)
diff --git a/src/core/content_browser_client_qt.h b/src/core/content_browser_client_qt.h
index 7c8aa3ac9..1ccd2926d 100644
--- a/src/core/content_browser_client_qt.h
+++ b/src/core/content_browser_client_qt.h
@@ -269,6 +269,8 @@ public:
 
 private:
     scoped_refptr<ShareGroupQtQuick> m_shareGroupQtQuick;
+    std::string m_appLocale;
+    std::string m_cachedQtLocale;
 };
 
 } // namespace QtWebEngineCore
diff --git a/src/core/web_engine_library_info.cpp b/src/core/web_engine_library_info.cpp
index 2ad5b7565..09a4141b0 100644
--- a/src/core/web_engine_library_info.cpp
+++ b/src/core/web_engine_library_info.cpp
@@ -46,6 +46,7 @@
 #include "components/spellcheck/spellcheck_buildflags.h"
 #include "content/public/common/content_paths.h"
 #include "sandbox/policy/switches.h"
+#include "ui/base/l10n/l10n_util.h"
 #include "ui/base/ui_base_paths.h"
 #include "ui/base/ui_base_switches.h"
 
@@ -353,18 +354,15 @@ base::string16 WebEngineLibraryInfo::getApplicationName()
 std::string WebEngineLibraryInfo::getApplicationLocale()
 {
     base::CommandLine *parsedCommandLine = base::CommandLine::ForCurrentProcess();
-    if (!parsedCommandLine->HasSwitch(switches::kLang)) {
+    if (parsedCommandLine->HasSwitch(switches::kLang)) {
+        return parsedCommandLine->GetSwitchValueASCII(switches::kLang);
+    } else {
         const QString &locale = QLocale().bcp47Name();
-
-        // QLocale::bcp47Name returns "en" for American English locale. Chromium requires the "US" suffix
-        // to clarify the dialect and ignores the shorter version.
-        if (locale == "en")
-            return "en-US";
-
-        return locale.toStdString();
+        std::string resolvedLocale;
+        if (l10n_util::CheckAndResolveLocale(locale.toStdString(), &resolvedLocale))
+            return resolvedLocale;
     }
-
-    return parsedCommandLine->GetSwitchValueASCII(switches::kLang);
+    return "en-US";
 }
 
 #if defined(OS_WIN)
diff --git a/tests/auto/widgets/qwebengineview/tst_qwebengineview.cpp b/tests/auto/widgets/qwebengineview/tst_qwebengineview.cpp
index 021986381..bf2c28ae6 100644
--- a/tests/auto/widgets/qwebengineview/tst_qwebengineview.cpp
+++ b/tests/auto/widgets/qwebengineview/tst_qwebengineview.cpp
@@ -123,6 +123,7 @@ private Q_SLOTS:
     void doNotBreakLayout();
 
     void changeLocale();
+    void mixLangLocale();
     void inputMethodsTextFormat_data();
     void inputMethodsTextFormat();
     void keyboardEvents();
@@ -1210,6 +1211,29 @@ void tst_QWebEngineView::changeLocale()
     QCOMPARE(errorLines.first().toUtf8(), QByteArrayLiteral("Die Website ist nicht erreichbar"));
 }
 
+void tst_QWebEngineView::mixLangLocale()
+{
+    for (QString locale : { "en_DK", "de_CH", "eu_ES" }) {
+        QLocale::setDefault(locale);
+        QWebEngineView view;
+        QSignalSpy loadSpy(&view, &QWebEngineView::loadFinished);
+
+        bool terminated = false;
+        auto sc = connect(view.page(), &QWebEnginePage::renderProcessTerminated, [&] () { terminated = true; });
+
+        view.load(QUrl("qrc:///resources/dummy.html"));
+        QTRY_VERIFY(terminated || loadSpy.count() == 1);
+
+        QVERIFY2(!terminated,
+            qPrintable(QString("Locale [%1] terminated: %2, loaded: %3").arg(locale).arg(terminated).arg(loadSpy.count())));
+        QVERIFY(loadSpy.first().first().toBool());
+
+        QString content = toPlainTextSync(view.page());
+        QVERIFY2(!content.isEmpty() && content.contains("test content"), qPrintable(content));
+    }
+    QLocale::setDefault(QLocale("en"));
+}
+
 void tst_QWebEngineView::inputMethodsTextFormat_data()
 {
     QTest::addColumn<QString>("string");