dgram: make send cb act as "error" event handler

This allows users to provide a callback that handles potential
errors resulting from a `socket.send` call. The original behavior
of emitting the error event on the socket is preserved.

Fixes: https://github.com/joyent/node/issues/4846
PR-URL: https://github.com/joyent/node/pull/7738
PR-URL: https://github.com/nodejs/io.js/pull/1796
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

1 files changed, 9 insertions, 1 deletions

diff --git a/lib/dgram.js b/lib/dgram.js
index 22dc7a2319..8cf5d30779 100644
--- a/lib/dgram.js
+++ b/lib/dgram.js
@@ -300,7 +300,15 @@ Socket.prototype.send = function(buffer,
 
   self._handle.lookup(address, function(ex, ip) {
     if (ex) {
-      if (callback) callback(ex);
+      if (callback) {
+        callback(ex);
+
+        if (self.listeners('error').length)
+          self.emit('error', ex);
+
+        return;
+      }
+
       self.emit('error', ex);
     } else if (self._handle) {
       var req = new SendWrap();