daemon: send stderr of service programs to the syslog
If git-daemon is run with --detach or --inetd, then stderr is explicitly
redirected to /dev/null. But notice that the service programs were spawned
via execl_git_cmd(), in particular, the stderr channel is inherited from
the daemon. This means that errors that the programs wrote to stderr (for
example, via die()), went to /dev/null.
This patch arranges that the daemon does not merely exec the service
program, but forks it and monitors stderr of the child; it writes the
errors that it produces to the daemons log via logerror().
A consequence is that the daemon process remains in memory for the full
duration of the service program, but this cannot be avoided.
Signed-off-by: Johannes Sixt <firstname.lastname@example.org>
Signed-off-by: Junio C Hamano <email@example.com>