[TxMt] Usability bug, Subversion bundle (Previous Summaries)

[Chris Thomas]

> I wrote a long, long commit message. I decided I wanted to refer to  
> an earlier message (so I'd remember what changes happened since the  
> last commit). I choose a "Previous Summary" from the menu. The  
> message-text area is filled with the historical text.
>
> Expected: I should be able to recover the message I was working on,  
> via a control or at least via Undo.
>
> Actual: My work on the message is destroyed.

Yikes. Added undo support in Subversion rev 5213.

It comes with a caveat: AppKit clears the undo stack when you change  
keyboard focus to a different UI element, so I don't know how  
reliable you'll find this initial implementation. We can tweak it if  
needed.

Thanks,
Chris