Don't clear lineedit in non normal echo mode when validation is invalid

This fixes a regression introduced with
c09e9f71173a698670d6c728291ee24f53d50800 which caused the lineedit to
clear the whole text when an invalid character was entered into a lineedit
with an echo mode that was not Normal and a validator was set.

Now if undo() is called directly then it will still clear the text as it
is considered to be called as a user. Whereas the validation will take
care of the invalid entry by using internalUndo() as before which avoids
the clearing of the entire text.

Task-number: QTBUG-29318
Change-Id: I5ff5777a75ab864de2217441b5f518f50646bd8f
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>

2 files changed, 18 insertions, 7 deletions

diff --git a/src/widgets/widgets/qwidgetlinecontrol.cpp b/src/widgets/widgets/qwidgetlinecontrol.cpp
index e6385ba390..7033eeea22 100644
--- a/src/widgets/widgets/qwidgetlinecontrol.cpp
+++ b/src/widgets/widgets/qwidgetlinecontrol.cpp
@@ -279,6 +279,23 @@ void QWidgetLineControl::clear()
     separate();
     finishChange(priorState, /*update*/false, /*edited*/false);
 }
+/*!
+    \internal
+
+    Undoes the previous operation.
+*/
+
+void QWidgetLineControl::undo()
+{
+    // Undo works only for clearing the line when in any of password the modes
+    if (m_echoMode == QLineEdit::Normal) {
+        internalUndo();
+        finishChange(-1, true);
+    } else {
+        cancelPasswordEchoTimer();
+        clear();
+    }
+}
 
 /*!
     \internal
@@ -1278,12 +1295,6 @@ void QWidgetLineControl::internalUndo(int until)
     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) {
diff --git a/src/widgets/widgets/qwidgetlinecontrol_p.h b/src/widgets/widgets/qwidgetlinecontrol_p.h
index f21d88177c..49d9413fc0 100644
--- a/src/widgets/widgets/qwidgetlinecontrol_p.h
+++ b/src/widgets/widgets/qwidgetlinecontrol_p.h
@@ -245,7 +245,7 @@ public:
 
     void insert(const QString &);
     void clear();
-    void undo() { internalUndo(); finishChange(-1, true); }
+    void undo();
     void redo() { internalRedo(); finishChange(); }
     void selectWordAtPos(int);