Suppress Ctrl/Ctrl+Shift keypresses in line/text edits.

Ctrl/Ctrl+Shift should not cause any characters to be input
(as opposed to AltGr(Alt+Ctrl) as used on German keyboards).

Extend the tests in QLineEdit and QPlainTextEdit to
check the modifiers, remove test from QTextEdit
since it is handled by QWidgetTextControl.

Task-number: QTBUG-35734
Change-Id: Ie0004fac68cf840c68247f27547e84b021355cd2
Reviewed-by: Gatis Paeglis <gatis.paeglis@digia.com>

src/widgets/widgets/qwidgetlinecontrol.cpp

@@ -1879,7 +1879,10 @@ void QWidgetLineControl::processKeyEvent(QKeyEvent* event)
         unknown = false;
     }
 
-    if (unknown && !isReadOnly()) {
+    // QTBUG-35734: ignore Ctrl/Ctrl+Shift; accept only AltGr (Alt+Ctrl) on German keyboards
+    if (unknown && !isReadOnly()
+        && event->modifiers() != Qt::ControlModifier
+        && event->modifiers() != (Qt::ControlModifier | Qt::ShiftModifier)) {
         QString t = event->text();
         if (!t.isEmpty() && t.at(0).isPrint()) {
             insert(t);

src/widgets/widgets/qwidgettextcontrol.cpp

@@ -1339,6 +1339,12 @@ void QWidgetTextControlPrivate::keyPressEvent(QKeyEvent *e)
 
 process:
     {
+        // QTBUG-35734: ignore Ctrl/Ctrl+Shift; accept only AltGr (Alt+Ctrl) on German keyboards
+        if (e->modifiers() == Qt::ControlModifier
+            || e->modifiers() == (Qt::ShiftModifier | Qt::ControlModifier)) {
+            e->ignore();
+            return;
+        }
         QString text = e->text();
         if (!text.isEmpty() && (text.at(0).isPrint() || text.at(0) == QLatin1Char('\t'))) {
             if (overwriteMode

tests/auto/widgets/widgets/qlineedit/tst_qlineedit.cpp

@@ -249,6 +249,7 @@ private slots:
 
     void editInvalidText();
 
+    void charWithAltOrCtrlModifier_data();
     void charWithAltOrCtrlModifier();
 
     void inlineCompletion();
@@ -3224,19 +3225,35 @@ void tst_QLineEdit::editInvalidText()
     testWidget->setValidator(0);
 }
 
+Q_DECLARE_METATYPE(Qt::KeyboardModifiers)
+
+void tst_QLineEdit::charWithAltOrCtrlModifier_data()
+{
+    QTest::addColumn<Qt::KeyboardModifiers>("modifiers");
+    QTest::addColumn<bool>("textExpected");
+    QTest::newRow("no-modifiers") << Qt::KeyboardModifiers() << true;
+    // Ctrl, Ctrl+Shift: No text (QTBUG-35734)
+    QTest::newRow("ctrl") << Qt::KeyboardModifiers(Qt::ControlModifier)
+        << false;
+    QTest::newRow("ctrl-shift") << Qt::KeyboardModifiers(Qt::ShiftModifier | Qt::ControlModifier)
+        << false;
+    QTest::newRow("alt") << Qt::KeyboardModifiers(Qt::AltModifier) << true;
+    // Alt-Ctrl (Alt-Gr on German keyboards, Task 129098): Expect text
+    QTest::newRow("alt-ctrl") << (Qt::AltModifier | Qt::ControlModifier) << true;
+}
+
 void tst_QLineEdit::charWithAltOrCtrlModifier()
 {
+    QFETCH(Qt::KeyboardModifiers, modifiers);
+    QFETCH(bool, textExpected);
+
     QLineEdit *testWidget = ensureTestWidget();
     testWidget->clear();
-    QCOMPARE(testWidget->text(), QString(""));
+    QVERIFY(testWidget->text().isEmpty());
-    QTest::keyPress(testWidget, Qt::Key_Plus);
+
-    QCOMPARE(testWidget->text(), QString("+"));
+    QTest::keyPress(testWidget, Qt::Key_Plus, modifiers);
-    QTest::keyPress(testWidget, Qt::Key_Plus, Qt::ControlModifier);
+    const QString expectedText = textExpected ?  QLatin1String("+") : QString();
-    QCOMPARE(testWidget->text(), QString("++"));
+    QCOMPARE(testWidget->text(), expectedText);
-    QTest::keyPress(testWidget, Qt::Key_Plus, Qt::AltModifier);
-    QCOMPARE(testWidget->text(), QString("+++"));
-    QTest::keyPress(testWidget, Qt::Key_Plus, Qt::AltModifier | Qt::ControlModifier);
-    QCOMPARE(testWidget->text(), QString("++++"));
 }
 
 void tst_QLineEdit::leftKeyOnSelectedText()

tests/auto/widgets/widgets/qplaintextedit/tst_qplaintextedit.cpp

@@ -99,7 +99,8 @@ private slots:
 #ifndef QT_NO_CLIPBOARD
     void copyAndSelectAllInReadonly();
 #endif
-    void ctrlAltInput();
+    void charWithAltOrCtrlModifier_data();
+    void charWithAltOrCtrlModifier();
     void noPropertiesOnDefaultTextEditCharFormat();
     void setPlainTextShouldEmitTextChangedOnce();
     void overwriteMode();
@@ -691,10 +692,34 @@ void tst_QPlainTextEdit::copyAndSelectAllInReadonly()
 }
 #endif
 
-void tst_QPlainTextEdit::ctrlAltInput()
+Q_DECLARE_METATYPE(Qt::KeyboardModifiers)
+
+// Test how QWidgetTextControlPrivate (used in QPlainTextEdit, QTextEdit)
+// handles input with modifiers.
+void tst_QPlainTextEdit::charWithAltOrCtrlModifier_data()
 {
-    QTest::keyClick(ed, Qt::Key_At, Qt::ControlModifier | Qt::AltModifier);
+    QTest::addColumn<Qt::KeyboardModifiers>("modifiers");
-    QCOMPARE(ed->toPlainText(), QString("@"));
+    QTest::addColumn<bool>("textExpected");
+
+    QTest::newRow("no-modifiers") << Qt::KeyboardModifiers() << true;
+    // Ctrl, Ctrl+Shift: No text (QTBUG-35734)
+    QTest::newRow("ctrl") << Qt::KeyboardModifiers(Qt::ControlModifier)
+        << false;
+    QTest::newRow("ctrl-shift") << Qt::KeyboardModifiers(Qt::ShiftModifier | Qt::ControlModifier)
+        << false;
+    QTest::newRow("alt") << Qt::KeyboardModifiers(Qt::AltModifier) << true;
+    // Alt-Ctrl (Alt-Gr on German keyboards, Task 129098): Expect text
+    QTest::newRow("alt-ctrl") << (Qt::AltModifier | Qt::ControlModifier) << true;
+}
+
+void tst_QPlainTextEdit::charWithAltOrCtrlModifier()
+{
+    QFETCH(Qt::KeyboardModifiers, modifiers);
+    QFETCH(bool, textExpected);
+
+    QTest::keyClick(ed, Qt::Key_At, modifiers);
+    const QString expectedText = textExpected ?  QLatin1String("@") : QString();
+    QCOMPARE(ed->toPlainText(), expectedText);
 }
 
 void tst_QPlainTextEdit::noPropertiesOnDefaultTextEditCharFormat()

tests/auto/widgets/widgets/qtextedit/tst_qtextedit.cpp

@@ -122,7 +122,6 @@ private slots:
 #ifndef QT_NO_CLIPBOARD
     void copyAndSelectAllInReadonly();
 #endif
-    void ctrlAltInput();
     void noPropertiesOnDefaultTextEditCharFormat();
     void setPlainTextShouldUseCurrentCharFormat();
     void setPlainTextShouldEmitTextChangedOnce();
@@ -1042,12 +1041,6 @@ void tst_QTextEdit::copyAndSelectAllInReadonly()
 }
 #endif
 
-void tst_QTextEdit::ctrlAltInput()
-{
-    QTest::keyClick(ed, Qt::Key_At, Qt::ControlModifier | Qt::AltModifier);
-    QCOMPARE(ed->toPlainText(), QString("@"));
-}
-
 void tst_QTextEdit::noPropertiesOnDefaultTextEditCharFormat()
 {
     // there should be no properties set on the default/initial char format