git: workaround old git-rev-parse(1) (--git-path)

git < 2.5.0 was missing --git-path support.  This means any
users relying on some rare environment variables will need git
2.5.0+

1 files changed, 5 insertions, 0 deletions

diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index 236f70c1..a4daaa48 100644
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -59,6 +59,11 @@ sub git_path ($$) {
         $self->{-git_path}->{$path} ||= do {
                 local $/ = "\n";
                 chomp(my $str = $self->qx(qw(rev-parse --git-path), $path));
+
+                # git prior to 2.5.0 did not understand --git-path
+                if ($str eq "--git-path\n$path") {
+                        $str = "$self->{git_dir}/$path";
+                }
                 $str;
         };
 }