The "undo" command:

Usage: fossil undo ?OPTIONS? ?FILENAME...?
or: fossil redo ?OPTIONS? ?FILENAME...?

The undo command reverts the changes caused by the previous command if the previous command is one of the following:

fossil update
fossil merge
fossil revert
fossil stash pop
fossil stash apply
fossil stash drop
fossil stash goto
fossil clean (*see note below*)

Note: The "fossil clean" command only saves state for files less than 10MiB in size and so if fossil clean deleted files larger than that, then "fossil undo" will not recover the larger files.

If FILENAME is specified then restore the content of the named file(s) but otherwise leave the update or merge or revert in effect. The redo command undoes the effect of the most recent undo.

If the -n|--dry-run option is present, no changes are made and instead the undo or redo command explains what actions the undo or redo would have done had the -n|--dry-run been omitted.

If the most recent command is not one of those listed as undoable, then the undo command might try to restore the state to be what it was prior to the last undoable command, or it might be a no-op. If in doubt about what the undo command will do, first run it with the -n option.

A single level of undo/redo is supported. The undo/redo stack is cleared by the commit and check-out commands. Other commands may or may not clear the undo stack.

Future versions of Fossil might add new commands to the set of commands that are undoable.

Options:

-n|--dry-run
Do not make changes, but show what would be done