From 67a5c76a1ca22f119a6b316faddb0cb3767060b7 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Thu, 11 Oct 2018 01:18:52 +0100
Subject: [PATCH] changedir_git_toplevel: Special error for not in git tree

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 Debian/Dgit.pm | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Debian/Dgit.pm b/Debian/Dgit.pm
index bfe2ab9b..458017df 100644
--- a/Debian/Dgit.pm
+++ b/Debian/Dgit.pm
@@ -502,6 +502,10 @@ sub git_rev_parse ($) {
 
 sub changedir_git_toplevel () {
     my $toplevel = cmdoutput qw(git rev-parse --show-toplevel);
+    length $toplevel or fail __ <<END;
+not in a git working tree?
+(git rev-parse --show-toplevel produced no output)
+END
     chdir $toplevel or fail f_ "chdir toplevel %s: %s\n", $toplevel, $!;
 }
 
-- 
2.30.2