From 75702a381ac408ebe78e237c729b295dc9d7bb49 Mon Sep 17 00:00:00 2001
From: "Kyle J. McKay" <mackyle@gmail.com>
Date: Sat, 12 Nov 2016 03:18:54 -0800
Subject: [PATCH] Util.pm: add is_git_dir function

The is_git_dir function returns true if Git would recognize
the specified directory as a Git directory.

Signed-off-by: Kyle J. McKay <mackyle@gmail.com>
---
 Girocco/Util.pm | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/Girocco/Util.pm b/Girocco/Util.pm
index eeb94c3..62b8fa0 100644
--- a/Girocco/Util.pm
+++ b/Girocco/Util.pm
@@ -22,7 +22,7 @@ BEGIN {
 			 calc_bigfilethreshold has_reserved_suffix
 			 noFatalsToBrowser calc_redeltathreshold
 			 clean_email_multi read_HEAD_symref read_config_file
-			 read_config_file_hash);
+			 read_config_file_hash is_git_dir);
 }
 
 my $encoder;
@@ -1141,4 +1141,28 @@ sub read_config_file_hash {
 	return \%config;
 }
 
+# similar to Git's test except that GIT_OBJECT_DIRECTORY is ignored
+sub is_git_dir {
+	my $gd = shift;
+	defined($gd) && $gd ne "" && -d $gd or return undef;
+	-d "$gd/objects" && -x "$gd/objects" or return 0;
+	-d "$gd/refs" && -x "$gd/refs" or return 0;
+	if (-l "$gd/HEAD") {
+		my $rl = readlink("$gd/HEAD");
+		defined($rl) && $rl =~ m,^refs/., or return 0;
+		-e "$gd/HEAD" or return 1;
+	}
+	open my $fd, '<', "$gd/HEAD" or return 0;
+	my $hv;
+	{
+		local $/;
+		$hv = <$fd>;
+	}
+	close $fd;
+	defined $hv or return 0;
+	chomp $hv;
+	$hv =~ m,^ref:\s*refs/., and return 1;
+	return $hv =~ /^[0-9a-f]{40}/;
+}
+
 1;
-- 
2.11.4.GIT