[PATCH v3] git-send-email: add option to specify sendmail command

@@ -167,6 +167,14 @@ Sending
 	`sendemail.envelopeSender` configuration variable; if that is
 	unspecified, choosing the envelope sender is left to your MTA.
 
+--sendmail-cmd=<command>::
+	Specify a command to run to send the email. The command should
+	be sendmail-like; specifically, it must support the `-i` option.
+	The command will be executed in the shell if necessary.  Default
+	is the value of `sendemail.sendmailcmd`.  If unspecified, and if
+	--smtp-server is also unspecified, git-send-email will search
+	for `sendmail` in `/usr/sbin`, `/usr/lib` and $PATH.
+
 --smtp-encryption=<encryption>::
 	Specify the encryption to use, either 'ssl' or 'tls'.  Any other
 	value reverts to plain SMTP.  Default is the value of

@@ -211,13 +219,16 @@ a password is obtained using 'git-credential'.
 
 --smtp-server=<host>::
 	If set, specifies the outgoing SMTP server to use (e.g.
-	`smtp.example.com` or a raw IP address).  Alternatively it can
-	specify a full pathname of a sendmail-like program instead;
-	the program must support the `-i` option.  Default value can
-	be specified by the `sendemail.smtpServer` configuration
-	option; the built-in default is to search for `sendmail` in
-	`/usr/sbin`, `/usr/lib` and $PATH if such program is
-	available, falling back to `localhost` otherwise.
+	`smtp.example.com` or a raw IP address).  If unspecified, and if
+	`--sendmail-cmd` is also unspecified, the default is to search
+	for `sendmail` in `/usr/sbin`, `/usr/lib` and $PATH if such a
+	program is available, falling back to `localhost` otherwise.
++
+For backward compatibility, this option can also specify a full pathname
+of a sendmail-like program instead; the program must support the `-i`
+option.  This method does not support passing arguments or using plain
+command names.  For those use cases, consider using `--sendmail-cmd`
+instead.
 
 --smtp-server-port=<port>::
 	Specifies a port different from the default port (SMTP

@@ -70,6 +70,7 @@ sub usage {
 
   Sending:
     --envelope-sender       <str>  * Email envelope sender.
+    --sendmail-cmd          <str>  * Command to run to send email.
     --smtp-server       <str:int>  * Outgoing SMTP server to use. The port
                                      is optional. Default 'localhost'.
     --smtp-server-option    <str>  * Outgoing SMTP server option to use.

@@ -252,6 +253,7 @@ sub do_edit {
 my (@suppress_cc);
 my ($auto_8bit_encoding);
 my ($compose_encoding);
+my ($sendmail_cmd);
 # Variables with corresponding config settings & hardcoded defaults
 my ($debug_net_smtp) = 0;		# Net::SMTP, see send_message()
 my $thread = 1;

@@ -299,6 +301,7 @@ sub do_edit {
     "assume8bitencoding" => \$auto_8bit_encoding,
     "composeencoding" => \$compose_encoding,
     "transferencoding" => \$target_xfer_encoding,
+    "sendmailcmd" => \$sendmail_cmd,
 );
 
 my %config_path_settings = (

@@ -432,6 +435,7 @@ sub read_config {
 		    "no-bcc" => \$no_bcc,
 		    "chain-reply-to!" => \$chain_reply_to,
 		    "no-chain-reply-to" => sub {$chain_reply_to = 0},
+		    "sendmail-cmd=s" => \$sendmail_cmd,
 		    "smtp-server=s" => \$smtp_server,
 		    "smtp-server-option=s" => \@smtp_server_options,
 		    "smtp-server-port=s" => \$smtp_server_port,

@@ -1003,16 +1007,19 @@ sub expand_one_alias {
 	$reply_to = sanitize_address($reply_to);
 }
 
-if (!defined $smtp_server) {
+if (!defined $sendmail_cmd && !defined $smtp_server) {
 	my @sendmail_paths = qw( /usr/sbin/sendmail /usr/lib/sendmail );
 	push @sendmail_paths, map {"$_/sendmail"} split /:/, $ENV{PATH};
 	foreach (@sendmail_paths) {
 		if (-x $_) {
-			$smtp_server = $_;
+			$sendmail_cmd = $_;
 			last;
 		}
 	}
-	$smtp_server ||= 'localhost'; # could be 127.0.0.1, too... *shrug*
+
+	if (!defined $sendmail_cmd) {
+		$smtp_server = 'localhost'; # could be 127.0.0.1, too... *shrug*
+	}
 }
 
 if ($compose && $compose > 0) {

@@ -1492,11 +1499,17 @@ sub send_message {
 
 	if ($dry_run) {
 		# We don't want to send the email.
-	} elsif (file_name_is_absolute($smtp_server)) {
+	} elsif (defined $sendmail_cmd || file_name_is_absolute($smtp_server)) {
 		my $pid = open my $sm, '|-';
 		defined $pid or die $!;
 		if (!$pid) {
-			exec($smtp_server, @sendmail_parameters) or die $!;
+			if (defined $sendmail_cmd) {
+				exec ("sh", "-c", "$sendmail_cmd \"\$@\"", "-", @sendmail_parameters)
+					or die $!;
+			} else {
+				exec ($smtp_server, @sendmail_parameters)
+					or die $!;
+			}
 		}
 		print $sm "$header\n$message";
 		close $sm or die $!;

@@ -1592,14 +1605,21 @@ sub send_message {
 		printf($dry_run ? __("Dry-Sent %s\n") : __("Sent %s\n"), $subject);
 	} else {
 		print($dry_run ? __("Dry-OK. Log says:\n") : __("OK. Log says:\n"));
-		if (!file_name_is_absolute($smtp_server)) {
+		if (!defined $sendmail_cmd && !file_name_is_absolute($smtp_server)) {
 			print "Server: $smtp_server\n";
 			print "MAIL FROM:<$raw_from>\n";
 			foreach my $entry (@recipients) {
 			    print "RCPT TO:<$entry>\n";
 			}
 		} else {
-			print "Sendmail: $smtp_server ".join(' ',@sendmail_parameters)."\n";
+			my $sm;
+			if (defined $sendmail_cmd) {
+				$sm = $sendmail_cmd;
+			} else {
+				$sm = $smtp_server;
+			}
+
+			print "Sendmail: $sm ".join(' ',@sendmail_parameters)."\n";
 		}
 		print $header, "\n";
 		if ($smtp) {

@@ -2148,6 +2148,37 @@ test_expect_success $PREREQ 'leading and trailing whitespaces are removed' '
 	test_cmp expected-list actual-list
 '
 
+test_expect_success $PREREQ 'test using command name with --sendmail-cmd' '
+	clean_fake_sendmail &&
+	PATH="$(pwd):$PATH" \
+	git send-email \
+		--from="Example <nobody@example.com>" \
+		--to=nobody@example.com \
+		--sendmail-cmd="fake.sendmail" \
+		HEAD^ &&
+	test_path_is_file commandline1
+'
+
+test_expect_success $PREREQ 'test using arguments with --sendmail-cmd' '
+	clean_fake_sendmail &&
+	git send-email \
+		--from="Example <nobody@example.com>" \
+		--to=nobody@example.com \
+		--sendmail-cmd="\"$(pwd)/fake.sendmail\" -f nobody@example.com" \
+		HEAD^ &&
+	test_path_is_file commandline1
+'
+
+test_expect_success $PREREQ 'test shell expression with --sendmail-cmd' '
+	clean_fake_sendmail &&
+	git send-email \
+		--from="Example <nobody@example.com>" \
+		--to=nobody@example.com \
+		--sendmail-cmd="f() { \"$(pwd)/fake.sendmail\" \"\$@\"; };f" \
+		HEAD^ &&
+	test_path_is_file commandline1
+'
+
 test_expect_success $PREREQ 'invoke hook' '
 	mkdir -p .git/hooks &&