send-email: support validate hook

Currently, send-email has support for rudimentary e-mail validation.
Allow the user to add support for more validation by providing a
sendemail-validate hook.

Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 19 insertions, 1 deletions

diff --git a/git-send-email.perl b/git-send-email.perl
index eea0a51..c314cc2 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -25,8 +25,9 @@ use Getopt::Long;
 use Text::ParseWords;
 use Term::ANSIColor;
 use File::Temp qw/ tempdir tempfile /;
-use File::Spec::Functions qw(catfile);
+use File::Spec::Functions qw(catdir catfile);
 use Error qw(:try);
+use Cwd qw(abs_path cwd);
 use Git;
 use Git::I18N;
 
@@ -1737,6 +1738,23 @@ sub unique_email_list {
 
 sub validate_patch {
 	my $fn = shift;
+
+	my $validate_hook = catfile(catdir($repo->repo_path(), 'hooks'),
+				    'sendemail-validate');
+	my $hook_error;
+	if (-x $validate_hook) {
+		my $target = abs_path($fn);
+		# The hook needs a correct cwd and GIT_DIR.
+		my $cwd_save = cwd();
+		chdir($repo->wc_path() or $repo->repo_path())
+			or die("chdir: $!");
+		local $ENV{"GIT_DIR"} = $repo->repo_path();
+		$hook_error = "rejected by sendemail-validate hook"
+			if system($validate_hook, $target);
+		chdir($cwd_save) or die("chdir: $!");
+	}
+	return $hook_error if $hook_error;
+
 	open(my $fh, '<', $fn)
 		or die sprintf(__("unable to open %s: %s\n"), $fn, $!);
 	while (my $line = <$fh>) {