[PATCH] Remove .git auto detection from setup_git_env()

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

When GIT_DIR environment variable is not specified, .git will be
searched if a repository is needed. Currently this can be done in two
places: setup_git_directory_gently() and setup_git_env().

The one in setup_git_env() is no longer correct and should IMHO have
been removed since the introduction of setup_git_directory_gently() in
d288a70. Having two ways of auto detection may lead to obscure errors
because .git may be misdetected by setup_git_env(),
automatically called via git_path(), which is all over the place.

This patch makes setup_git_env() die if GIT_DIR is not explictly
set. That's setup_git_directory_gently()'s job. If you ever want to
touch things inside $GIT_DIR, you should have already called
setup_git_directory_gently().

This patch breaks commands (in a good way) and obviously not for
mainline. I still have to go through "make test" to see how many are
impacted. But I think this is a good change. Am I missing something?

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 environment.c |    4 +---
 setup.c       |    4 +++-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/environment.c b/environment.c
index 739ec27..b609569 100644
--- a/environment.c
+++ b/environment.c
@@ -67,9 +67,7 @@ static void setup_git_env(void)
 {
 	git_dir = getenv(GIT_DIR_ENVIRONMENT);
 	if (!git_dir)
-		git_dir = read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
-	if (!git_dir)
-		git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
+		die("GIT_DIR not properly set");
 	git_object_dir = getenv(DB_ENVIRONMENT);
 	if (!git_object_dir) {
 		git_object_dir = xmalloc(strlen(git_dir) + 9);
diff --git a/setup.c b/setup.c
index 710e2f3..ae1ba52 100644
--- a/setup.c
+++ b/setup.c
@@ -396,8 +396,10 @@ const char *setup_git_directory_gently(int *nongit_ok)
 				die("Repository setup failed");
 			break;
 		}
-		if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
+		if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT)) {
+			set_git_dir(DEFAULT_GIT_DIR_ENVIRONMENT);
 			break;
+		}
 		if (is_git_directory(".")) {
 			inside_git_dir = 1;
 			if (!work_tree_env)
-- 
1.7.0.rc0.54.gd33ef