From b6ea85a601ddac9cb0716d8cb4d446439fa0778f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Josef=20Kemetm=C3=BCller?= <josef.kemetmueller@ims.co.at>
Date: Fri, 27 May 2022 11:40:49 +0200
Subject: [PATCH] scmdiff: Hardcode `--git-dir`

The newest version of git refuses to work on repositories not owned by
the current user. This leads to issues with the /api/scmdiff endpoint:

May 27 11:16:05 myhydra hydra-server[923698]: fatal: unsafe repository ('/var/lib/hydra/scm/git/57ea036ec7ecd85c8dd085e02ecc6f12dd5c079a6203d16aea49f586cadfb2be' is owned by someone else)
May 27 11:16:05 myhydra hydra-server[923698]: To add an exception for this directory, call:
May 27 11:16:05 myhydra hydra-server[923698]:         git config --global --add safe.directory /var/lib/hydra/scm/git/57ea036ec7ecd85c8dd085e02ecc6f12dd5c079a6203d16aea49f586cadfb2be
May 27 11:16:05 myhydra hydra-server[923701]: warning: Not a git repository. Use --no-index to compare two paths outside a working tree
May 27 11:16:05 myhydra hydra-server[923701]: usage: git diff --no-index [<options>] <path> <path>

I used the same solution that was used in NixOS/nix#6440.

Fixes #1214
---
 src/lib/Hydra/Controller/API.pm | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/lib/Hydra/Controller/API.pm b/src/lib/Hydra/Controller/API.pm
index 6f10ef57..8ebed599 100644
--- a/src/lib/Hydra/Controller/API.pm
+++ b/src/lib/Hydra/Controller/API.pm
@@ -216,8 +216,8 @@ sub scmdiff : Path('/api/scmdiff') Args(0) {
     } elsif ($type eq "git") {
         my $clonePath = getSCMCacheDir . "/git/" . sha256_hex($uri);
         die if ! -d $clonePath;
-        $diff .= `(cd $clonePath; git log $rev1..$rev2)`;
-        $diff .= `(cd $clonePath; git diff $rev1..$rev2)`;
+        $diff .= `(cd $clonePath; git --git-dir .git log $rev1..$rev2)`;
+        $diff .= `(cd $clonePath; git --git-dir .git diff $rev1..$rev2)`;
     }
 
     $c->stash->{'plain'} = { data => (scalar $diff) || " " };