Fixes #877. Don't wait for socket pool to establish connections.

Thanks to Yann Biancheri for putting together an initial test.

lib/http.js

@@ -1152,12 +1152,6 @@ Agent.prototype.appendMessage = function(options) {
   this.queue.push(req);
   req._queue = this.queue;
 
-  /*
-  req.on('finish', function () {
-    self._cycle();
-  });
-  */
-
   this._cycle();
 
   return req;
@@ -1374,8 +1368,6 @@ Agent.prototype._cycle = function() {
   var first = this.queue[0];
   if (!first) return;
 
-  var haveConnectingSocket = false;
-
   // First try to find an available socket.
   for (var i = 0; i < this.sockets.length; i++) {
     var socket = this.sockets[i];
@@ -1395,13 +1387,11 @@ Agent.prototype._cycle = function() {
       self._cycle(); // try to dispatch another
       return;
     }
-
-    if (socket._httpConnecting) haveConnectingSocket = true;
   }
 
   // If no sockets are connecting, and we have space for another we should
   // be starting a new connection to handle this request.
-  if (!haveConnectingSocket && this.sockets.length < this.maxSockets) {
+  if (this.sockets.length < this.maxSockets) {
     this._establishNewConnection();
   }
 

test/simple/test-regress-GH-877.js

@@ -0,0 +1,49 @@
+var common = require('../common');
+var http = require('http');
+var assert = require('assert');
+
+var N = 20;
+var responses = 0;
+var maxQueued = 0;
+
+debugger;
+
+var agent = http.getAgent('127.0.0.1', common.PORT);
+agent.maxSockets = 10;
+
+var server = http.createServer(function (req, res) {
+  res.writeHead(200);
+  res.end('Hello World\n');
+});
+
+server.listen(common.PORT, "127.0.0.1", function() {
+  for (var i = 0; i < N; i++) {
+    var options = {
+      host: '127.0.0.1',
+      port: common.PORT,
+    };
+
+    debugger;
+
+    var req = http.get(options, function(res) {
+      if (++responses == N) {
+        server.close();
+      }
+    });
+
+    assert.equal(req.agent, agent);
+
+    console.log('Socket: ' + agent.sockets.length +
+                '/' + agent.maxSockets +
+                ' queued: '+ agent.queue.length);
+
+    if (maxQueued < agent.queue.length)  {
+      maxQueued = agent.queue.length;
+    }
+  }
+});
+
+process.on('exit', function() {
+  assert.ok(responses == N);
+  assert.ok(maxQueued <= 10);
+});