When the fsmonitor daemon is spawned as a background process, it may
inherit file descriptors from its parent that it does not need. In
particular, when the test harness or a CI system captures output through
pipes, the daemon can inherit duplicated pipe endpoints. If the daemon
holds these open, the parent process never sees EOF and may appear to
hang.
Set close_fd_above_stderr on the child process at daemon startup so
that file descriptors 3 and above are closed before any daemon work
begins. This ensures the daemon does not inadvertently hold open
descriptors from its launching environment.
Additionally, call setsid() when the daemon starts with --detach to
create a new session and process group. Without this, shells that
enable job control (e.g. bash with "set -m") treat the daemon as part
of the spawning command's job. Their "wait" builtin then blocks until
the daemon exits, which it never does. This specifically affects
systems where /bin/sh is bash (e.g. Fedora), since dash only waits for
the specific PID rather than the full process group.
Add a 30-second timeout to "fsmonitor--daemon stop" so it does
not block indefinitely if the daemon fails to shut down.
Signed-off-by: Paul Tarjan <github@paulisageek.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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