undo

Overview ¶

Package undo saves, restores, and redoes checkout state in a Fossil .fslckout database.

The undo state machine uses a vvar entry "undo_available":

0 — nothing saved
1 — undo available (Save was called)
2 — redo available (Undo was called)

Only one level of undo/redo is kept; each Save replaces any previous state.