Redirect stdin *before* we establish a listen socket

This way we'll avoid listening on fd=0 and have a better
chance of having fd=0 as /dev/null


git-svn-id: https://svn.musicpd.org/mpd/branches/branch-0.13.0-fixes@7174 09075e82-0dd4-0310-85a5-a0d7c8717e4f

1 files changed, 29 insertions, 0 deletions

diff --git a/src/listen.c b/src/listen.c
index 323bf430f..da8482e4e 100644
--- a/src/listen.c
+++ b/src/listen.c
@@ -50,6 +50,34 @@ static int *listenSockets;
 static int numberOfListenSockets;
 static int boundPort;
 
+/*
+ * redirect stdin to /dev/null to work around a libao bug
+ * there are likely other bugs in other libraries (and even our code!)
+ * that check for fd > 0, so it's easiest to just keep
+ * fd = 0 == /dev/null for now...
+ */
+static void redirect_stdin(void)
+{
+	int fd, st;
+	struct stat ss;
+
+	if ((st = fstat(STDIN_FILENO, &ss)) < 0) {
+		if ((fd = open("/dev/null", O_RDONLY) > 0)) {
+			DEBUG("stdin closed, and could not open /dev/null "
+			      "as fd=0, some external library bugs "
+			      "may be exposed...\n");
+			close(fd);
+		}
+		return;
+	}
+	if (!isatty(STDIN_FILENO))
+		return;
+	if ((fd = open("/dev/null", O_RDONLY)) < 0)
+		FATAL("failed to open /dev/null %s\n", strerror(errno));
+	if (dup2(fd, STDIN_FILENO) < 0)
+		FATAL("dup2 stdin: %s\n", strerror(errno));
+}
+
 static int establishListen(unsigned int port,
                            struct sockaddr *addrp, socklen_t addrlen)
 {
@@ -196,6 +224,7 @@ void listenOnPort(void)
 
 	boundPort = port;
 
+	redirect_stdin();
 	do {
 		parseListenConfigParam(port, param);
 	} while ((param = getNextConfigParam(CONF_BIND_TO_ADDRESS, param)));