[PATCH] send-email: automatic envelope sender

[Felipe Contreras <felipe.contreras@gmail.com>]

This adds the option to specify the envelope sender as "auto" which
would pick the 'from' address. This is good because now we can specify
the address only in one place (and change it easily).

Comments by Junio C Hamano.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
---
 Documentation/git-send-email.txt |    7 ++++---
 git-send-email.perl              |    6 +++++-
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/Documentation/git-send-email.txt b/Documentation/git-send-email.txt
index c85d7f4..8c482f4 100644
--- a/Documentation/git-send-email.txt
+++ b/Documentation/git-send-email.txt
@@ -108,9 +108,10 @@ Sending
 --envelope-sender=<address>::
 	Specify the envelope sender used to send the emails.
 	This is useful if your default address is not the address that is
-	subscribed to a list. If you use the sendmail binary, you must have
-	suitable privileges for the -f parameter. Default is the value of
-	the 'sendemail.envelopesender' configuration variable; if that is
+	subscribed to a list. In order to use the 'From' address, set the
+	value to "auto". If you use the sendmail binary, you must have
+	suitable privileges for the -f parameter.  Default is the value of the
+	'sendemail.envelopesender' configuration variable; if that is
 	unspecified, choosing the envelope sender is left to your MTA.
 
 --smtp-encryption=<encryption>::
diff --git a/git-send-email.perl b/git-send-email.perl
index 4f5da4e..da2e56e 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -862,7 +862,11 @@ X-Mailer: git-send-email $gitversion
 
 	my @sendmail_parameters = ('-i', @recipients);
 	my $raw_from = $sanitized_sender;
-	$raw_from = $envelope_sender if (defined $envelope_sender);
+	if (defined $envelope_sender) {
+		if (not $envelope_sender eq "auto") {
+			$raw_from = $envelope_sender;
+		}
+	}
 	$raw_from = extract_valid_address($raw_from);
 	unshift (@sendmail_parameters,
 			'-f', $raw_from) if(defined $envelope_sender);
-- 
1.6.6.rc0.61.geeb75