Vi 에서 Undo 할 수 없을 때까지 Undo 하는 방법...

in gvim

:help undo

1. Undo and redo commands				*undo-commands*

<Undo>		or					*undo* *<Undo>* *u*
u			Undo [count] changes.  {Vi: only one level}

							*:u* *:un* *:undo*
:u[ndo]			Undo one change.  {Vi: only one level}

							*CTRL-R*
CTRL-R			Redo [count] changes which were undone.  {Vi: redraw
			screen}

							*:red* *:redo* *redo*
:red[o]			Redo one change which was undone.  {Vi: no redo}