3 files changed, 90 insertions, 2 deletions

diff --git a/src/widgets/widgets/qwidgetlinecontrol.cpp b/src/widgets/widgets/qwidgetlinecontrol.cpp
index 6920354e73..ba7e2ddacf 100644
--- a/src/widgets/widgets/qwidgetlinecontrol.cpp
+++ b/src/widgets/widgets/qwidgetlinecontrol.cpp
@@ -1279,6 +1279,13 @@ void QWidgetLineControl::internalUndo(int until)
         return;
     cancelPasswordEchoTimer();
     internalDeselect();
+
+    // Undo works only for clearing the line when in any of password the modes
+    if (m_echoMode != QLineEdit::Normal) {
+        clear();
+        return;
+    }
+
     while (m_undoState && m_undoState > until) {
         Command& cmd = m_history[--m_undoState];
         switch (cmd.type) {
@@ -1868,6 +1875,21 @@ void QWidgetLineControl::processKeyEvent(QKeyEvent* event)
         event->accept();
 }
 
+bool QWidgetLineControl::isUndoAvailable() const
+{
+    // For security reasons undo is not available in any password mode (NoEcho included)
+    // with the exception that the user can clear the password with undo.
+    return !m_readOnly && m_undoState
+            && (m_echoMode == QLineEdit::Normal || m_history[m_undoState - 1].type == QWidgetLineControl::Insert);
+}
+
+bool QWidgetLineControl::isRedoAvailable() const
+{
+    // Same as with undo. Disabled for password modes.
+    return !m_readOnly
+            && m_echoMode == QLineEdit::Normal
+            && m_undoState < m_history.size();
+}
 
 QT_END_NAMESPACE
 
diff --git a/src/widgets/widgets/qwidgetlinecontrol_p.h b/src/widgets/widgets/qwidgetlinecontrol_p.h
index ba3b202bda..2dce790c1e 100644
--- a/src/widgets/widgets/qwidgetlinecontrol_p.h
+++ b/src/widgets/widgets/qwidgetlinecontrol_p.h
@@ -125,8 +125,8 @@ public:
         return (c != -1 ? c : 0);
     }
 
-    bool isUndoAvailable() const { return !m_readOnly && m_undoState; }
-    bool isRedoAvailable() const { return !m_readOnly && m_undoState < (int)m_history.size(); }
+    bool isUndoAvailable() const;
+    bool isRedoAvailable() const;
     void clearUndo() { m_history.clear(); m_modifiedState = m_undoState = 0; }
 
     bool isModified() const { return m_modifiedState != m_undoState; }
diff --git a/tests/auto/widgets/widgets/qlineedit/tst_qlineedit.cpp b/tests/auto/widgets/widgets/qlineedit/tst_qlineedit.cpp
index 956f970b85..ed53a133e4 100644
--- a/tests/auto/widgets/widgets/qlineedit/tst_qlineedit.cpp
+++ b/tests/auto/widgets/widgets/qlineedit/tst_qlineedit.cpp
@@ -287,6 +287,9 @@ private slots:
     void inputMethodQueryImHints_data();
     void inputMethodQueryImHints();
 
+    void undoRedoAndEchoModes_data();
+    void undoRedoAndEchoModes();
+
 protected slots:
     void editingFinished();
 
@@ -3954,5 +3957,68 @@ void tst_QLineEdit::inputMethodQueryImHints()
     QCOMPARE(static_cast<Qt::InputMethodHints>(value.toInt()), hints);
 }
 
+void tst_QLineEdit::undoRedoAndEchoModes_data()
+{
+    QTest::addColumn<int>("echoMode");
+    QTest::addColumn<QStringList>("input");
+    QTest::addColumn<QStringList>("expected");
+
+    QStringList input(QList<QString>() << "aaa" << "bbb" << "ccc");
+
+    QTest::newRow("Normal")
+        << (int) QLineEdit::Normal
+        << input
+        << QStringList(QList<QString>() << "aaa" << "ccc" << "");
+
+    QTest::newRow("NoEcho")
+        << (int) QLineEdit::NoEcho
+        << input
+        << QStringList(QList<QString>() << "" << "" << "");
+
+    QTest::newRow("Password")
+        << (int) QLineEdit::Password
+        << input
+        << QStringList(QList<QString>() << "" << "" << "");
+
+    QTest::newRow("PasswordEchoOnEdit")
+        << (int) QLineEdit::PasswordEchoOnEdit
+        << input
+        << QStringList(QList<QString>() << "" << "" << "");
+}
+
+void tst_QLineEdit::undoRedoAndEchoModes()
+{
+    QFETCH(int, echoMode);
+    QFETCH(QStringList, input);
+    QFETCH(QStringList, expected);
+
+    // create some history for the QLineEdit
+    testWidget->clear();
+    testWidget->setEchoMode(QLineEdit::EchoMode(echoMode));
+    testWidget->insert(input.at(0));
+    testWidget->selectAll();
+    testWidget->backspace();
+    testWidget->insert(input.at(1));
+
+    // test undo
+    QVERIFY(testWidget->isUndoAvailable());
+    testWidget->undo();
+    QCOMPARE(testWidget->text(), expected.at(0));
+    testWidget->insert(input.at(2));
+    testWidget->selectAll();
+    testWidget->backspace();
+    QCOMPARE(testWidget->isUndoAvailable(), echoMode == QLineEdit::Normal);
+    testWidget->undo();
+    QCOMPARE(testWidget->text(), expected.at(1));
+
+    // test redo
+    QCOMPARE(testWidget->isRedoAvailable(), echoMode == QLineEdit::Normal);
+    testWidget->redo();
+    QCOMPARE(testWidget->text(), expected.at(2));
+    QVERIFY(!testWidget->isRedoAvailable());
+    testWidget->redo();
+    QCOMPARE(testWidget->text(), expected.at(2));
+}
+
 QTEST_MAIN(tst_QLineEdit)
 #include "tst_qlineedit.moc"