send-email: add sendmail email aliases format

Teach send-email to read aliases in the sendmail aliases format, i.e.

	<alias>: <address|alias>[, <address|alias>...]

Examples:

	alice: Alice W Land <awol@example.com>
	bob: Robert Bobbyton <bob@example.com>
	# this is a comment
	   # this is also a comment
	chloe: chloe@example.com
	abgroup: alice, bob
	bcgrp: bob, chloe, Other <o@example.com>

 - Quoted aliases and quoted addresses are not supported.
 - Line continuations are not supported.

Warnings are printed for explicitly unsupported constructs, and any
other lines that are not matched by the parser.

Signed-off-by: Allen Hubbe <allenbh@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/git-send-email.perl b/git-send-email.perl
index e1e9b14..6bedf74 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -516,6 +516,31 @@ my %parse_alias = (
 			  }
 		      } },
 
+	sendmail => sub { my $fh = shift; while (<$fh>) {
+		# ignore blank lines and comment lines
+		if (/^\s*(?:#.*)?$/) { }
+
+		# warn on lines that contain quotes
+		elsif (/"/) {
+			print STDERR "sendmail alias with quotes is not supported: $_\n";
+		}
+
+		# warn on lines that continue
+		elsif (/^\s|\\$/) {
+			print STDERR "sendmail continuation line is not supported: $_\n";
+		}
+
+		# recognize lines that look like an alias
+		elsif (/^(\S+?)\s*:\s*(.+)$/) {
+			my ($alias, $addr) = ($1, $2);
+			$aliases{$alias} = [ split_addrs($addr) ];
+		}
+
+		# warn on lines that are not recognized
+		else {
+			print STDERR "sendmail line is not recognized: $_\n";
+		}}},
+
 	gnus => sub { my $fh = shift; while (<$fh>) {
 		if (/\(define-mail-alias\s+"(\S+?)"\s+"(\S+?)"\)/) {
 			$aliases{$1} = [ $2 ];