[PATCH] http-push: fail when info/refs exists and is already locked

Rationale:

Failing instead of silently not updating remote refs makes the things cleare
for the user when trying to push on a repository while another person do (or
while a dandling locks are waiting for a 10 minutes timeout).

When silently not updating remote refs, the user does not even know that git
has pushed the objects but leaved the refs as they were before (e.g. a new
bunch of commits on branch "master" is uploaded, however the branch by itsel
still points on the previous head commit).
---
 http-push.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/http-push.c b/http-push.c
index 2c4e91d..e1984d3 100644
--- a/http-push.c
+++ b/http-push.c

@@ -2243,6 +2243,11 @@ int main(int argc, char **argv)
 		info_ref_lock = lock_remote("info/refs", LOCK_TIME);
 		if (info_ref_lock)
 			remote->can_update_info_refs = 1;
+		else {
+			fprintf(stderr, "Error: cannot lock existing info/refs\n");
+			rc = 1;
+			goto cleanup;
+		}
 	}
 	if (remote->has_info_packs)
 		fetch_indices();

-- 
1.5.4.rc3.52.g9a5bd-dirty