[PATCH 1/2] remote: avoid reading $GIT_DIR config in non-repo

From: Jeff King <peff@peff.net>
Date: Feb 14, 2017, 20:33 UTC
Message-ID: <20170214203327.icdvrhwpmarvwe5y@sigill.intra.peff.net>
In-Reply-To: <20170214203117.xnln6ahb3l32agqb@sigill.intra.peff.net>

The "git ls-remote" command can be run outside of a repository, but needs to look up configured remotes. The config code is smart enough to handle this case itself, but we also check the historical "branches" and "remotes" paths in $GIT_DIR. The git_path() function causes us to blindly look at ".git/remotes", even if we know we aren't in a git repository.

For now, this is just an unlikely bug (you probably don't have such a file if you're not in a repository), but it will become more obvious once we merge b1ef400ee (setup_git_env: avoid blind fall-back to ".git", 2016-10-20):

  [now]
  $ git ls-remote
  fatal: No remote configured to list refs from.

  [with b1ef400ee]
  $ git ls-remote
  fatal: BUG: setup_git_env called without repository

We can fix this by skipping these sources entirely when we're outside of a repository.

The test is a little more complex than the demonstration above. Rather than detect the correct behavior by parsing the error message, we can actually set up a case where the remote name we give is a valid repository, but b1ef400ee would cause us to die in the configuration step.

This test doesn't fail now, but it future-proofs us for the b1ef400ee change.

Signed-off-by: Jeff King <peff@peff.net>
---
 remote.c             | 2 +-
 t/t5512-ls-remote.sh | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/remote.c b/remote.c
index bf1bf2309..9f83fe2c4 100644
--- a/remote.c
+++ b/remote.c
@@ -693,7 +693,7 @@ static struct remote *remote_get_1(const char *name,
 		name = get_default(current_branch, &name_given);
 
 	ret = make_remote(name, 0);
-	if (valid_remote_nick(name)) {
+	if (valid_remote_nick(name) && have_git_dir()) {
 		if (!valid_remote(ret))
 			read_remotes_file(ret);
 		if (!valid_remote(ret))
diff --git a/t/t5512-ls-remote.sh b/t/t5512-ls-remote.sh
index 55fc83fc0..94fc9be9c 100755
--- a/t/t5512-ls-remote.sh
+++ b/t/t5512-ls-remote.sh
@@ -248,4 +248,13 @@ test_expect_success PIPE,JGIT,GIT_DAEMON 'indicate no refs in standards-complian
 	test_expect_code 2 git ls-remote --exit-code git://localhost:$JGIT_DAEMON_PORT/empty.git
 '
 
+test_expect_success 'ls-remote works outside repository' '
+	# It is important for this repo to be inside the nongit
+	# area, as we want a repo name that does not include
+	# slashes (because those inhibit some of our configuration
+	# lookups).
+	nongit git init --bare dst.git &&
+	nongit git ls-remote dst.git
+'
+
 test_done

-- 
2.12.0.rc1.479.g59880b11e