edirs-merge
edirs-merge is an alias for `ediff-merge-directories' in `ediff.el
'.
(edirs-merge DIR1 DIR2 REGEXP &optional MERGE-AUTOSTORE-DIR)
Run Ediff on a pair of directories, DIR1 and DIR2, merging files that have
the same name in both. The third argument, REGEXP, is nil or a regular
expression; only file names that match the regexp are considered.