[PATCH 31/34] watch: use our own "git credential" wrapper

[Eric Wong <e@yhbt.net>]

Git.pm may not be installed on some systems; or some users have
multiple Perl installations and Git.pm is not available to the
Perl running -watch.  Accomodate both those types of users by
providing our own "git credential" wrapper.
---
 MANIFEST                         |  1 +
 lib/PublicInbox/GitCredential.pm | 40 ++++++++++++++++++++++++++++++++
 lib/PublicInbox/WatchMaildir.pm  | 22 ++++++++----------
 3 files changed, 51 insertions(+), 12 deletions(-)
 create mode 100644 lib/PublicInbox/GitCredential.pm

diff --git a/MANIFEST b/MANIFEST
index f9d1eea5bd9..6de2c72581b 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -123,6 +123,7 @@ lib/PublicInbox/Filter/Vger.pm
 lib/PublicInbox/GetlineBody.pm
 lib/PublicInbox/Git.pm
 lib/PublicInbox/GitAsyncCat.pm
+lib/PublicInbox/GitCredential.pm
 lib/PublicInbox/GitHTTPBackend.pm
 lib/PublicInbox/GzipFilter.pm
 lib/PublicInbox/HTTP.pm
diff --git a/lib/PublicInbox/GitCredential.pm b/lib/PublicInbox/GitCredential.pm
new file mode 100644
index 00000000000..826e7a55e8b
--- /dev/null
+++ b/lib/PublicInbox/GitCredential.pm
@@ -0,0 +1,40 @@
+# Copyright (C) 2020 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+package PublicInbox::GitCredential;
+use strict;
+use PublicInbox::Spawn qw(popen_rd);
+
+sub run ($$) {
+	my ($self, $op) = @_;
+	my ($in_r, $in_w);
+	pipe($in_r, $in_w) or die "pipe: $!";
+	my $out_r = popen_rd([qw(git credential), $op], undef, { 0 => $in_r });
+	close $in_r or die "close in_r: $!";
+
+	my $out = '';
+	for my $k (qw(url protocol host username password)) {
+		defined(my $v = $self->{$k}) or next;
+		die "`$k' contains `\\n' or `\\0'\n" if $v =~ /[\n\0]/;
+		$out .= "$k=$v\n";
+	}
+	$out .= "\n";
+	print $in_w $out or die "print (git credential $op): $!";
+	close $in_w or die "close (git credential $op): $!";
+	return $out_r if $op eq 'fill';
+	<$out_r> and die "unexpected output from `git credential $op'\n";
+	close $out_r or die "`git credential $op' failed: \$!=$! \$?=$?\n";
+}
+
+sub fill {
+	my ($self) = @_;
+	my $out_r = run($self, 'fill');
+	while (<$out_r>) {
+		chomp;
+		return if $_ eq '';
+		/\A([^=]+)=(.*)\z/ or die "bad line: $_\n";
+		$self->{$1} = $2;
+	}
+	close $out_r or die "git credential fill failed: \$!=$! \$?=$?\n";
+}
+
+1;
diff --git a/lib/PublicInbox/WatchMaildir.pm b/lib/PublicInbox/WatchMaildir.pm
index 43c8395c79b..19f894d4315 100644
--- a/lib/PublicInbox/WatchMaildir.pm
+++ b/lib/PublicInbox/WatchMaildir.pm
@@ -308,13 +308,14 @@ sub auth_anon_cb { '' }; # for Mail::IMAPClient::Authcallback
 sub mic_for ($$$) { # mic = Mail::IMAPClient
 	my ($self, $url, $mic_args) = @_;
 	my $uri = PublicInbox::URIimap->new($url);
-	my $cred = {
+	require PublicInbox::GitCredential;
+	my $cred = bless {
 		url => $url,
 		protocol => $uri->scheme,
 		host => $uri->host,
 		username => $uri->user,
 		password => $uri->password,
-	};
+	}, 'PublicInbox::GitCredential';
 	my $common = $mic_args->{uri_section($uri)} // {};
 	my $host = $cred->{host};
 	my $mic_arg = {
@@ -342,7 +343,7 @@ sub mic_for ($$$) { # mic = Mail::IMAPClient
 		$cred = undef;
 	}
 	if ($cred) {
-		Git::credential($cred, 'fill'); # may prompt user here
+		$cred->fill; # may prompt user here
 		$mic->User($mic_arg->{User} = $cred->{username});
 		$mic->Password($mic_arg->{Password} = $cred->{password});
 	} else { # AUTH=ANONYMOUS
@@ -356,7 +357,7 @@ sub mic_for ($$$) { # mic = Mail::IMAPClient
 		warn "E: <$url> LOGIN: $@\n";
 		$mic = undef;
 	}
-	Git::credential($cred, $mic ? 'approve' : 'reject') if $cred;
+	$cred->run($mic ? 'approve' : 'reject') if $cred;
 	$mic;
 }
 
@@ -653,8 +654,6 @@ sub watch_imap_init ($) {
 	my ($self) = @_;
 	eval { require PublicInbox::IMAPClient } or
 		die "Mail::IMAPClient is required for IMAP:\n$@\n";
-	eval { require Git } or
-		die "Git (Perl module) is required for IMAP:\n$@\n";
 	eval { require PublicInbox::IMAPTracker } or
 		die "DBD::SQLite is required for IMAP\n:$@\n";
 
@@ -772,11 +771,12 @@ sub nn_for ($$$) { # nn = Net::NNTP
 	my $cred;
 	my ($u, $p);
 	if (defined(my $ui = $uri->userinfo)) {
-		$cred = {
+		require PublicInbox::GitCredential;
+		$cred = bless {
 			url => $sec,
 			protocol => uri_scheme($uri),
 			host => $uri->host,
-		};
+		}, 'PublicInbox::GitCredential';
 		($u, $p) = split(/:/, $ui, 2);
 		($cred->{username}, $cred->{password}) = ($u, $p);
 	}
@@ -791,7 +791,7 @@ sub nn_for ($$$) { # nn = Net::NNTP
 	my $nn = nn_new($nn_arg, $nntp_opt, $url);
 
 	if ($cred) {
-		Git::credential($cred, 'fill'); # may prompt user here
+		$cred->fill; # may prompt user here
 		if ($nn->authinfo($u, $p)) {
 			push @{$nntp_opt->{-postconn}}, [ 'authinfo', $u, $p ];
 		} else {
@@ -818,7 +818,7 @@ W: see https://rt.cpan.org/Ticket/Display.html?id=129967 for updates
 	}
 
 	$self->{nn_arg}->{$sec} = $nn_arg;
-	Git::credential($cred, $nn ? 'approve' : 'reject') if $cred;
+	$cred->run($nn ? 'approve' : 'reject') if $cred;
 	$nn;
 }
 
@@ -896,8 +896,6 @@ sub watch_nntp_init ($) {
 	my ($self) = @_;
 	eval { require Net::NNTP } or
 		die "Net::NNTP is required for NNTP:\n$@\n";
-	eval { require Git } or
-		die "Git (Perl module) is required for NNTP:\n$@\n";
 	eval { require PublicInbox::IMAPTracker } or
 		die "DBD::SQLite is required for NNTP\n:$@\n";