30.1.12.6 Preparing Patches

When collaborating on projects it is common to send patches via email, to share changes. You can do this using VC with the vc-prepare-patch command. This will prompt you for the revisions you wish to share, and which destination email address(es) to use. Separate the revisions using the value of crm-separator, commas by default. The command will then prepare those revisions using your MUA (Mail User Agent) for you to review and send.

When invoked interactively in a Log View buffer with marked revisions, those marked revisions will be used.

Depending on the value of the user option vc-prepare-patches-separately, vc-prepare-patch will generate one or more messages. The default value t means prepare and display a message for each revision, one after another. A value of nil means to generate a single message with all patches attached in the body.

If you expect to contribute patches on a regular basis, you can set the user option vc-default-patch-addressee to the address(es) you wish to use. This will be used as the default value when invoking vc-prepare-patch. Project maintainers may consider setting this as a directory local variable (see Per-Directory Local Variables).