[PATCH 6/7] git: speed up ->git_path for non-worktrees

[Eric Wong <e@80x24.org>]

Only worktrees need to use `git rev-parse --git-path', so avoid
the spawn overhead of a new process.  With the SolverGit.pm
limit on coderepo scans disabled and scanning over 800 git repos
for git@vger matches, this reduces up xt/solver.t times by
roughly 25%.
---
 lib/PublicInbox/Git.pm | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/lib/PublicInbox/Git.pm b/lib/PublicInbox/Git.pm
index fe834210..6c7c11b6 100644
--- a/lib/PublicInbox/Git.pm
+++ b/lib/PublicInbox/Git.pm
@@ -99,15 +99,15 @@ sub new {
 
 sub git_path ($$) {
 	my ($self, $path) = @_;
-	$self->{-git_path}->{$path} //= do {
+	$self->{-git_path}->{$path} // do {
+		return "$self->{git_dir}/$path" if -d $self->{git_dir};
+
 		local $/ = "\n";
-		chomp(my $str = $self->qx(qw(rev-parse --git-path), $path));
+		chomp(my $s = $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;
+		$self->{-git_path}->{$path} = $s eq "--git-path\n$path" ?
+						"$self->{git_dir}/$path" : $s;
 	};
 }