net: fix net.Server.listen({fd:x}) error reporting

* don't assert when fd isn't an open file descriptor

* don't die with a ReferenceError when fd isn't a file descriptor
  you can listen() on

Fixes #3699.

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/net.js b/lib/net.js
index f129c0cce..f5d3ebdd2 100644
--- a/lib/net.js
+++ b/lib/net.js
@@ -851,6 +851,7 @@ var createServerHandle = exports._createServerHandle =
       default:
         // Not a fd we can listen on.  This will trigger an error.
         debug('listen invalid fd=' + fd + ' type=' + type);
+        global.errno = 'EINVAL'; // hack, callers expect that errno is set
         handle = null;
         break;
     }