Tab key is overwriting in overwrite mode

[Henning Holm]

(FF22, Win7) If you switch into overwrite mode using the insert key, trying to indent using the tab key overwrites the upcoming letters in the line.

This behaviour is different from most other editors I know. I can't really see a case where it could be wanted this way.

(Block indent works in overwrite mode, so if you just select anything in one line, indenting is possible.)

[Karsten Becker]

This is a failure within ACE Editor, not sure how to fix