Thanks to _noth_ for the patch, this fixes Mantis bug #1534

_noth_ wrote:
> When MPD is launched from a non-interactive shell, it enters an endless
> loop, filling up its error log file with "error accept()'ing" messages.
> This is caused by the fact that stdin is already closed when mpd starts
> up.  listenOnPort() opens up the first of its sockets as fd 0 (the first
> empty fd table position). Then, setup_log_output()->redirect_stdin()
> overwrites fd0 (fd=open("/dev/null",...); dup2(fd, STDIN_FILENO);)
> without checking if it corresponds to the actual standard input (or if
> it is open in the first place).  This means that listenSockets[0].fd now
> is a fd for /dev/null, thus doIOForInterfaces()->getConnections() can't
> accept(2) on it and fails with the above error. The attached patch fixes
> this for me.

git-svn-id: https://svn.musicpd.org/mpd/trunk@6843 09075e82-0dd4-0310-85a5-a0d7c8717e4f