[PATCH v2] commit: skip discarding the index if there is no pre-commit hook

[Kevin Willford <kewillf@microsoft.com>]

If there is not a pre-commit hook, there is no reason to discard
the index and reread it.

This change checks to presence of a pre-commit hook and then only
discards the index if there was one.

Signed-off-by: Kevin Willford <kewillf@microsoft.com>
---
 builtin/commit.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/builtin/commit.c b/builtin/commit.c
index e7a2cb6285..ab71b93518 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -940,12 +940,15 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 		return 0;
 	}
 
-	/*
-	 * Re-read the index as pre-commit hook could have updated it,
-	 * and write it out as a tree.  We must do this before we invoke
-	 * the editor and after we invoke run_status above.
-	 */
-	discard_cache();
+	if (!no_verify && find_hook("pre-commit")) {
+		/*
+		 * Re-read the index as pre-commit hook could have updated it,
+		 * and write it out as a tree.  We must do this before we invoke
+		 * the editor and after we invoke run_status above.
+		 */
+		discard_cache();
+	}
+
 	read_cache_from(index_file);
 	if (update_main_cache_tree(0)) {
 		error(_("Error building trees"));
-- 
2.14.1.481.g785c1dc9ae