#13 Justification buttons "stick"

[Anonymous]

Under certain conditions, the "left justification" button
remains "stuck" on while one of the right/center/full
justification buttons are also on.

It happens in several situations. The easiest to
reproduce is:

1. Start the editor
2. Type "Test", and press enter.
3. Type "Testing", and press enter.
4. Click (once) on the word "Testing".
5. Click the Right justification button.
6. Click the Left justification button.

Repeat steps 5 and 6 a few times.

Eventually, both the Right and Left justification buttons
will appear "pressed" at the same time.