Redo doesn't reset modified flag correctly

Hello

I have an issue with undo/redo and the modified flag of a SyntaxEditors document.
When I undo until a point where the document was not modified, it correctly sets the modified flag to false, but when I use redo, it sets modified to false one "step" after the document is back to unmodified state.

Example:

1)
Document
---------------------------------------------
Saved Saved Saved

at this point I set the modified flag to false, since the user has pressed save.

2)
I then Add some more text

Document
---------------------------------------------
Saved Saved Saved new text that is not saved

Modified: true (Correct)

3)
I undo so that my new text is removed going back to:

Document
---------------------------------------------
Saved Saved Saved


Modified: false (correct)

4)
I Undo one more step.

Document
---------------------------------------------


Modified: true (correct)

5)
I then redo again

Document
---------------------------------------------
Saved Saved Saved

Modified: true (incorrect)

6)
One more redo

Document
---------------------------------------------
Saved Saved Saved new text that is not saved

Modified: false (incorrect)


As can be seen in step 6, I get the flag set to false by redo, but it is done one step too late.

So, is this a bug, or am I doing something wrong when I reset the modified flag?

Sincerily
Roy Arvenäs, TAT