open any doc in the editor. type 1 char undo twice assert. the problem is the doc mod count is being modified even though undo may have done nothing, due to an empty undo stack. in fact, virtually all the logic of undo should be skipped if the undo stack is empty. Use nsITransactionManager::GetNumberOfUndoItems to check. Redo should be guarded the same way.

setting to M7, not serious enough to address during the M6 endgame.

This is my bug. The mod count stuff isn't done yet. Kin and I talked about how it should work.

Assign.

Assert commented out until mod count handling is done.

IS this something I'll be able to verify? If not, can one of you verify this one and mark it VERIFIED_FIXED ? thanks!

verified in 6/16 build...I simply typed a char then hit undo twice and no crash occurred...is that all to this one?

sujay, you'll never see asserts in optimized builds, and this one didn't cause a crash, so you can't verify this. But I will.