fix: socket.destroyed always be undefined on 0.10.x

lib/_http_agent.js

@@ -35,7 +35,7 @@ if (node10) {
     }
   };
 } else {
-  debug = util.debuglog('http');
+  debug = util.debuglog('agentkeepalive');
 }
 
 // New Agent code.
@@ -233,6 +233,11 @@ Agent.prototype.createSocket = function(req, options) {
 
   function onClose(err) {
     debug('CLIENT socket onClose');
+    // fix: socket.destroyed always be undefined on 0.10.x
+    if (typeof s.destroyed !== 'boolean') {
+      s.destroyed = true;
+    }
+
     // This is the only place where sockets get removed from the Agent.
     // If you want to remove a socket from the pool, just close it.
     // All socket errors end in a close event anyway.

lib/agent.js

@@ -31,7 +31,7 @@ if (node10) {
     }
   };
 } else {
-  debug = util.debuglog('http');
+  debug = util.debuglog('agentkeepalive');
 }
 
 module.exports = Agent;
@@ -76,7 +76,7 @@ Agent.prototype.createSocket = function (req, options) {
   var socket = OriginalAgent.prototype.createSocket.call(this, req, options);
   if (this.keepAlive) {
     // Disable Nagle's algorithm: http://blog.caustik.com/2012/04/08/scaling-node-js-to-100k-concurrent-connections/
-    // http://fengmk2.cnpmjs.org/benchmark/nagle-algorithm-delayed-ack-mock.html
+    // http://fengmk2.com/benchmark/nagle-algorithm-delayed-ack-mock.html
     socket.setNoDelay(true);
   }
   this.createSocketCount++;