Add a single entry to the given mailmap object. If the entry already exists, it will be replaced with the new entry.
mailmap to add the entry to
the real name to use, or NULL
the real email to use, or NULL
the name to replace, or NULL
the email to replace
0 on success, or an error code
See Implementation
Add a single entry to the given mailmap object. If the entry already exists, it will be replaced with the new entry.