format-patch: allow forcing the use of in-body From: header

Users may be authoring and committing their commits under the same
e-mail address they use to send their patches from, in which case
they shouldn't need to use the in-body From: line in their outgoing
e-mails.  At the receiving end, "git am" will use the address on the
"From:" header of the incoming e-mail and all should be well.

Some mailing lists, however, mangle the From: address from what the
original sender had; in such a situation, the user may want to add
the in-body "From:" header even for their own patches.

"git format-patch --[no-]force-in-body-from" was invented for such
users.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index be797d7a28..7c7f244e57 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -275,6 +275,15 @@ header). Note also that `git send-email` already handles this
 transformation for you, and this option should not be used if you are
 feeding the result to `git send-email`.
 
+--[no-]force-in-body-from::
+	With the e-mail sender specified via the `--from` option, by
+	default, an in-body "From:" to identify the real author of
+	the commit is added at the top of the commit log message if
+	the sender is different from the author.  With this option,
+	the in-body "From:" is added even when the sender and the
+	author have the same name and address, which may help if the
+	mailing list software mangles the sender's identity.
+
 --add-header=<header>::
 	Add an arbitrary header to the email headers.  This is in addition
 	to any configured headers, and may be used multiple times.