git-send-email.perl: Add --to-cmd

Add the ability to use a command line --to-cmd=cmd
to create the list of "To:" addresses.

Used a shared routine for --cc-cmd and --to-cmd.

Did not use IPC::Open2, leaving that for Ævar if
ever he decides to fix the other bugs he might find.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-send-email.txt

@@ -97,7 +97,7 @@ See the CONFIGURATION section for 'sendemail.multiedit'.
 	Specify the primary recipient of the emails generated. Generally, this
 	will be the upstream maintainer of the project involved. Default is the
 	value of the 'sendemail.to' configuration value; if that is unspecified,
-	this will be prompted for.
+	and --to-cmd is not specified, this will be prompted for.
 +
 The --to option must be repeated for each user you want on the to list.
 
@@ -177,6 +177,12 @@ user is prompted for a password while the input is masked for privacy.
 Automating
 ~~~~~~~~~~
 
+--to-cmd=<command>::
+	Specify a command to execute once per patch file which
+	should generate patch file specific "To:" entries.
+	Output of this command must be single email address per line.
+	Default is the value of 'sendemail.tocmd' configuration value.
+
 --cc-cmd=<command>::
 	Specify a command to execute once per patch file which
 	should generate patch file specific "Cc:" entries.

git-send-email.perl

@@ -70,6 +70,7 @@ sub usage {
 
   Automating:
     --identity              <str>  * Use the sendemail.<id> options.
+    --to-cmd                <str>  * Email To: via `<str> \$patch_path`
     --cc-cmd                <str>  * Email Cc: via `<str> \$patch_path`
     --suppress-cc           <str>  * author, self, sob, cc, cccmd, body, bodycc, all.
     --[no-]signed-off-by-cc        * Send to Signed-off-by: addresses. Default on.
@@ -187,7 +188,8 @@ sub do_edit {
 }
 
 # Variables with corresponding config settings
-my ($thread, $chain_reply_to, $suppress_from, $signed_off_by_cc, $cc_cmd);
+my ($thread, $chain_reply_to, $suppress_from, $signed_off_by_cc);
+my ($to_cmd, $cc_cmd);
 my ($smtp_server, $smtp_server_port, $smtp_authuser, $smtp_encryption);
 my ($identity, $aliasfiletype, @alias_files, @smtp_host_parts, $smtp_domain);
 my ($validate, $confirm);
@@ -214,6 +216,7 @@ sub do_edit {
     "smtppass" => \$smtp_authpass,
 	"smtpdomain" => \$smtp_domain,
     "to" => \@to,
+    "tocmd" => \$to_cmd,
     "cc" => \@initial_cc,
     "cccmd" => \$cc_cmd,
     "aliasfiletype" => \$aliasfiletype,
@@ -272,6 +275,7 @@ sub signal_handler {
                     "in-reply-to=s" => \$initial_reply_to,
 		    "subject=s" => \$initial_subject,
 		    "to=s" => \@to,
+		    "to-cmd=s" => \$to_cmd,
 		    "no-to" => \$no_to,
 		    "cc=s" => \@initial_cc,
 		    "no-cc" => \$no_cc,
@@ -711,7 +715,7 @@ ($)
 	$prompting++;
 }
 
-if (!@to) {
+if (!@to && !defined $to_cmd) {
 	my $to = ask("Who should the emails be sent to? ");
 	push @to, parse_address_line($to) if defined $to; # sanitized/validated later
 	$prompting++;
@@ -1238,21 +1242,10 @@ sub send_message {
 	}
 	close F;
 
-	if (defined $cc_cmd && !$suppress_cc{'cccmd'}) {
-		open(F, "$cc_cmd \Q$t\E |")
-			or die "(cc-cmd) Could not execute '$cc_cmd'";
-		while(<F>) {
-			my $c = $_;
-			$c =~ s/^\s*//g;
-			$c =~ s/\n$//g;
-			next if ($c eq $sender and $suppress_from);
-			push @cc, $c;
-			printf("(cc-cmd) Adding cc: %s from: '%s'\n",
-				$c, $cc_cmd) unless $quiet;
-		}
-		close F
-			or die "(cc-cmd) failed to close pipe to '$cc_cmd'";
-	}
+	push @to, recipients_cmd("to-cmd", "to", $to_cmd, $t)
+		if defined $to_cmd;
+	push @cc, recipients_cmd("cc-cmd", "cc", $cc_cmd, $t)
+		if defined $cc_cmd && !$suppress_cc{'cccmd'};
 
 	if ($broken_encoding{$t} && !$has_content_type) {
 		$has_content_type = 1;
@@ -1310,6 +1303,30 @@ sub send_message {
 	$message_id = undef;
 }
 
+# Execute a command (e.g. $to_cmd) to get a list of email addresses
+# and return a results array
+sub recipients_cmd {
+	my ($prefix, $what, $cmd, $file) = @_;
+
+	my $sanitized_sender = sanitize_address($sender);
+	my @addresses = ();
+	open(F, "$cmd \Q$file\E |")
+	    or die "($prefix) Could not execute '$cmd'";
+	while(<F>) {
+		my $address = $_;
+		$address =~ s/^\s*//g;
+		$address =~ s/\s*$//g;
+		$address = sanitize_address($address);
+		next if ($address eq $sanitized_sender and $suppress_from);
+		push @addresses, $address;
+		printf("($prefix) Adding %s: %s from: '%s'\n",
+		       $what, $address, $cmd) unless $quiet;
+		}
+	close F
+	    or die "($prefix) failed to close pipe to '$cmd'";
+	return @addresses;
+}
+
 cleanup_compose_files();
 
 sub cleanup_compose_files() {

t/t9001-send-email.sh

@@ -201,6 +201,24 @@ test_expect_success $PREREQ 'Prompting works' '
 		grep "^To: to@example.com\$" msgtxt1
 '
 
+test_expect_success $PREREQ 'tocmd works' '
+	clean_fake_sendmail &&
+	cp $patches tocmd.patch &&
+	echo tocmd--tocmd@example.com >>tocmd.patch &&
+	{
+	  echo "#!$SHELL_PATH"
+	  echo sed -n -e s/^tocmd--//p \"\$1\"
+	} > tocmd-sed &&
+	chmod +x tocmd-sed &&
+	git send-email \
+		--from="Example <nobody@example.com>" \
+		--to-cmd=./tocmd-sed \
+		--smtp-server="$(pwd)/fake.sendmail" \
+		tocmd.patch \
+		&&
+	grep "^To: tocmd@example.com" msgtxt1
+'
+
 test_expect_success $PREREQ 'cccmd works' '
 	clean_fake_sendmail &&
 	cp $patches cccmd.patch &&