Debugger: Clear undo/redo stacks when debugging session is finished

Task-number: QTCREATORBUG-7645
Change-Id: I17df03c5765129c21f38df19ea90c04e937a7217
Reviewed-by: hjk <hjk121@nokiamail.com>

src/plugins/debugger/logwindow.cpp

@@ -198,6 +198,13 @@ public:
         appendPlainText(text);
     }
 
+    void clearUndoRedoStacks()
+    {
+        if (!isUndoRedoEnabled())
+            return;
+        setUndoRedoEnabled(false);
+        setUndoRedoEnabled(true);
+    }
 
 private slots:
     void saveContents();
@@ -527,6 +534,12 @@ QString LogWindow::inputContents() const
     return m_inputText->toPlainText();
 }
 
+void LogWindow::clearUndoRedoStacks()
+{
+    m_inputText->clearUndoRedoStacks();
+    m_combinedText->clearUndoRedoStacks();
+}
+
 QString LogWindow::logTimeStamp()
 {
     // Cache the last log time entry by ms. If time progresses,