Usability: Undo

It's interesting, emacs has no concept of redo, a result of consecutive undos it's just a new state which in turn can be undone.

In the usual implementation of undo / redo when any changes are done after a series of undos all undo states are lost. From one side it is correct, and from the other side it is not. If the states were really wrong, the user will not remember about it and all is good, but if I drew a path in Photoshop, undo it, painted again... decided that at the first time I did it better and oops ...


Similarly, realization back/next in browsers bothered me until bookmarks support appeared.

True, in emacs also not everything is clean, to undo a part of a series of consecutive undos I need to type some useless keys combination to force emacs record the state. I would prefer undo sequence happens in the quasi mode: C-x C-u and while I hold Control and type then state fixing does not occur, if I make a mistake then I release Control the state is recorded and I can undo it again without changing my hands position.