ENH: ctkConsole: Restore positions after building the completion model

Since some implementation of updateCompletionModel (e.g python)
can display messages while building the completion model, it is
important to save and restore the positions.

Libs/Widgets/ctkConsole.cpp

@@ -544,9 +544,22 @@ void ctkConsolePrivate::updateCompleter()
     text_cursor.setPosition(this->InteractivePosition, QTextCursor::KeepAnchor);
     QString commandText = text_cursor.selectedText();
 
+    // Save current positions: Since some implementation of
+    // updateCompletionModel (e.g python) can display messages
+    // while building the completion model, it is important to save
+    // and restore the positions.
+    int savedInteractivePosition = this->InteractivePosition;
+    int savedCursorPosition = this->textCursor().position();
+
     // Call the completer to update the completion model
     this->Completer->updateCompletionModel(commandText);
 
+    // Restore positions
+    this->InteractivePosition = savedInteractivePosition;
+    QTextCursor textCursor = this->textCursor();
+    textCursor.setPosition(savedCursorPosition);
+    this->setTextCursor(textCursor);
+
     // Place and show the completer if there are available completions
     if (this->Completer->completionCount())
       {