sigprocmask: Avoid crashes through signal() on MSVC 9.

[gnulib.git] / lib / listen.c

diff --git a/lib/listen.c b/lib/listen.c
index 938aa75..b7d070e 100644 (file)
--- a/lib/listen.c
+++ b/lib/listen.c
@@ -32,9 +32,18 @@ int
 rpl_listen (int fd, int backlog)
 {
   SOCKET sock = FD_TO_SOCKET (fd);
-  int r = listen (sock, backlog);
-  if (r < 0)
-    set_winsock_errno ();
 
-  return r;
+  if (sock == INVALID_SOCKET)
+    {
+      errno = EBADF;
+      return -1;
+    }
+  else
+    {
+      int r = listen (sock, backlog);
+      if (r < 0)
+        set_winsock_errno ();
+
+      return r;
+    }
 }