Qt Linguist crashes because clearSelection() is called with an invalid QTextEdit

Detailed steps to reproduce this crash:

1. Open Qt Linguist
2. With mouse drag in it some .ts -file, eg. qt_folder\translations\assistant_cs.ts
3. Select and copy (ctrl+c) the contents of the translation field
4. With mouse drag in it some .ts -file which is not related to current open file at all, e.g. qt_folder\translations\designer_de.ts
5. Click "yes" in the appeared message box when asking if the previous file should be closed
6. Click on the translation field.
-> Qt Linguist crashes

A Quick fix for this issue:

In linguist\messageeditor.h, include QPointer

#include <QPointer>

and then change the line:

QTextEdit *m_selectionHolder;

to:

QPointer<QTextEdit> m_selectionHolder;