DialogButtonBox: don't change button text that has been explicitly set

If a custom button is declared in a DialogButtonBox, qsTr() will take
care of translation, and so we shouldn't touch it.

Amends c18c7bd7f9596e5ad3d13876a91203e1ceba2544.

Change-Id: I06221002cf850882f5318cf0a3ed86da35274d0c
Fixes: QTBUG-81796
Reviewed-by: Andy Shaw <andy.shaw@qt.io>

3 files changed, 120 insertions, 2 deletions

diff --git a/src/quicktemplates2/qquickdialogbuttonbox.cpp b/src/quicktemplates2/qquickdialogbuttonbox.cpp
index 33b720ed..d448aeed 100644
--- a/src/quicktemplates2/qquickdialogbuttonbox.cpp
+++ b/src/quicktemplates2/qquickdialogbuttonbox.cpp
@@ -455,8 +455,11 @@ void QQuickDialogButtonBoxPrivate::updateLanguage()
                 qmlAttachedPropertiesObject<QQuickDialogButtonBox>(button, true));
             const auto boxAttachedPrivate = QQuickDialogButtonBoxAttachedPrivate::get(attached);
             const QPlatformDialogHelper::StandardButton standardButton = boxAttachedPrivate->standardButton;
-            const QString buttonText = QGuiApplicationPrivate::platformTheme()->standardButtonText(standardButton);
-            button->setText(QPlatformTheme::removeMnemonics(buttonText));
+            // The button might be a custom one with explicitly specified text, so we shouldn't change it in that case.
+            if (standardButton != QPlatformDialogHelper::NoButton) {
+                const QString buttonText = QGuiApplicationPrivate::platformTheme()->standardButtonText(standardButton);
+                button->setText(QPlatformTheme::removeMnemonics(buttonText));
+            }
         }
         --i;
     }
diff --git a/tests/auto/translation/data/dialogButtonBoxWithCustomButtons.qml b/tests/auto/translation/data/dialogButtonBoxWithCustomButtons.qml
new file mode 100644
index 00000000..6f046cf1
--- /dev/null
+++ b/tests/auto/translation/data/dialogButtonBoxWithCustomButtons.qml
@@ -0,0 +1,75 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.14
+import QtQuick.Controls 2.14
+
+Item {
+    property Dialog dialog: Dialog {
+        width: 300
+        height: 300
+        visible: true
+
+        footer: DialogButtonBox {
+            Button {
+                objectName: "okButton"
+                text: qsTr("OK")
+
+                DialogButtonBox.buttonRole: DialogButtonBox.AcceptRole
+            }
+            Button {
+                objectName: "cancelButton"
+                text: qsTr("Cancel")
+
+                DialogButtonBox.buttonRole: DialogButtonBox.RejectRole
+            }
+        }
+    }
+}
diff --git a/tests/auto/translation/tst_translation.cpp b/tests/auto/translation/tst_translation.cpp
index 9cbca915..992c30a2 100644
--- a/tests/auto/translation/tst_translation.cpp
+++ b/tests/auto/translation/tst_translation.cpp
@@ -53,6 +53,7 @@ class tst_translation : public QQmlDataTest
 
 private slots:
     void dialogButtonBox();
+    void dialogButtonBoxWithCustomButtons();
 };
 
 void tst_translation::dialogButtonBox()
@@ -95,6 +96,45 @@ void tst_translation::dialogButtonBox()
     QCOMPARE(discardButton->text(), translatedDiscardText);
 }
 
+// Test that custom buttons with explicitly specified text
+// do not have that text overwritten on language changes.
+void tst_translation::dialogButtonBoxWithCustomButtons()
+{
+    // This is just a way of simulating the translator going out of scope
+    // after the QML has been loaded.
+    QScopedPointer<QTranslator> translator(new QTranslator);
+    // Doesn't matter which language it is, as we won't be using it anyway.
+    QVERIFY(translator->load(":/i18n/qtbase_fr.qm"));
+    QVERIFY(qApp->installTranslator(translator.data()));
+
+    QQuickView view(testFileUrl("dialogButtonBoxWithCustomButtons.qml"));
+    if (view.status() != QQuickView::Ready)
+        QFAIL("Failed to load QML file");
+    view.show();
+    QVERIFY(QTest::qWaitForWindowActive(&view));
+
+    QQuickDialog *dialog = view.rootObject()->property("dialog").value<QQuickDialog*>();
+    QVERIFY(dialog);
+
+    QQuickDialogButtonBox *dialogButtonBox = qobject_cast<QQuickDialogButtonBox*>(dialog->footer());
+    QVERIFY(dialogButtonBox);
+
+    auto okButton = dialogButtonBox->findChild<QQuickAbstractButton*>("okButton");
+    QVERIFY(okButton);
+    QCOMPARE(okButton->text(), QLatin1String("OK"));
+
+    QQuickAbstractButton *cancelButton = dialogButtonBox->findChild<QQuickAbstractButton*>("cancelButton");
+    QVERIFY(cancelButton);
+    QCOMPARE(cancelButton->text(), QLatin1String("Cancel"));
+
+    // Delete the translator and hence cause a LanguageChange event,
+    // but _without_ calling QQmlEngine::retranslate(), which would
+    // restore the original bindings and hence not reproduce the issue.
+    translator.reset();
+    QCOMPARE(okButton->text(), QLatin1String("OK"));
+    QCOMPARE(cancelButton->text(), QLatin1String("Cancel"));
+}
+
 QTEST_MAIN(tst_translation)
 
 #include "tst_translation.moc"