credential-cache: ignore "connection refused" errors
The credential-cache helper will try to connect to its
daemon over a unix socket. Originally, a failure to do so
was silently ignored, and we would either give up (if
performing a "get" or "erase" operation), or spawn a new
daemon (for a "store" operation).
But since 8ec6c8d, we try to report more errors. We detect a
missing daemon by checking for ENOENT on our connection
attempt. If the daemon is missing, we continue as before
(giving up or spawning a new daemon). For any other error,
we die and report the problem.
However, checking for ENOENT is not sufficient for a missing
daemon. We might also get ECONNREFUSED if a dead daemon
process left a stale socket. This generally shouldn't
happen, as the daemon cleans up after itself, but the daemon
may not always be given a chance to do so (e.g., power loss,
The resulting state is annoying not just because the helper
outputs an extra useless message, but because it actually
blocks the helper from spawning a new daemon to replace the
Fix it by checking for ECONNREFUSED.
Signed-off-by: Jeff King <email@example.com>
Signed-off-by: Junio C Hamano <firstname.lastname@example.org>