Arbitrary Patching with delta-patch

A general purpose, though low-level tool for merging is the delta-patch command:

% arx delta-patch FROM TO UPON OUTPUT-DIR

computes a patch set from FROM to TO and applies that patch set to UPON storing the result in OUTPUT-DIR.

The arguments FROM, TO, and UPON can be the names of (any) revision, or the directory names of project trees.

If UPON is a project tree, you can modify that tree directly with the --in-place option:

% arx delta-patch --in-place FROM TO UPON

Note: You pretty much have to know what you're doing to use this command. Normally, you should use star-merge, update or replay.