- Create new empty presentation.
- Insert a custom text box on a slide,
- Select Bullets On/Off to enable list style
- Enter some text at level 1
- Press enter
- Press tab
- Enter some text on level 2
- Press enter
- Press shift tab
- You are now on line three at level 1 and your text box 
  should look like the following (where | denotes the cursor):

*some text
  * some text
*|

- Now press backspace.
- The result is the following:

*some text
*some text|

- This is unexpected since line 2 seems to have changed its list 
  level during deletion of line 3.
- Internally, this is not the case: Press ESC to finish editing.
- The text box rearranges again to:

*some text
  * some text

- This is the expected result, but it should already have been 
  displayed during the edit operation.