From e3cf0975f9074f221974f7f7c82389786854999d Mon Sep 17 00:00:00 2001
From: Rory Prendergast <rory.prendergast@tanium.com>
Date: Tue, 2 Jan 2018 10:51:13 -0800
Subject: [PATCH] Adds whitelist for GIT_* env vars containing only GIT_SSH

---
 pre_commit/util.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/pre_commit/util.py b/pre_commit/util.py
index 10d78d99..a0eb3764 100644
--- a/pre_commit/util.py
+++ b/pre_commit/util.py
@@ -76,8 +76,11 @@ def no_git_env():
     # while running pre-commit hooks in submodules.
     # GIT_DIR: Causes git clone to clone wrong thing
     # GIT_INDEX_FILE: Causes 'error invalid object ...' during commit
+
+    # list of explicitly whitelisted variables
+    allowed_git_envs = ['GIT_SSH']
     return {
-        k: v for k, v in os.environ.items() if not k.startswith('GIT_')
+        k: v for k, v in os.environ.items() if not k.startswith('GIT_') or k in allowed_git_envs
     }