http: avoid create new socket

when active sockets reach max sockets limit

lib/_http_agent.js

@@ -86,7 +86,7 @@ function Agent(options) {
         if (self.sockets[name])
           count += self.sockets[name].length;
 
-        if (count >= self.maxSockets || freeLen >= self.maxFreeSockets) {
+        if (count > self.maxSockets || freeLen >= self.maxFreeSockets) {
           self.removeSocket(socket, options);
           socket.destroy();
         } else {

test/simple/test-http-agent-maxsockets.js

@@ -0,0 +1,74 @@
+// Copyright Joyent, Inc. and other Node contributors.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to permit
+// persons to whom the Software is furnished to do so, subject to the
+// following conditions:
+//
+// The above copyright notice and this permission notice shall be included
+// in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
+// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+// USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+var common = require('../common');
+var assert = require('assert');
+var http = require('http');
+
+var agent = new http.Agent({
+  keepAlive: true,
+  keepAliveMsecs: 1000,
+  maxSockets: 2,
+  maxFreeSockets: 2
+});
+
+var server = http.createServer(function(req, res) {
+  res.end('hello world');
+});
+
+function get(path, callback) {
+  return http.get({
+    host: 'localhost',
+    port: common.PORT,
+    agent: agent,
+    path: path
+  }, callback);
+}
+
+var count = 0;
+function done() {
+  if (++count !== 2) {
+    return;
+  }
+  var freepool = agent.freeSockets[Object.keys(agent.freeSockets)[0]];
+  assert.equal(freepool.length, 2,
+      'expect keep 2 free sockets, but got ' + freepool.length);
+  agent.destroy();
+  server.close();
+}
+
+server.listen(common.PORT, function() {
+  get('/1', function(res) {
+    assert.equal(res.statusCode, 200);
+    res.resume();
+    res.on('end', function() {
+      process.nextTick(done);
+    });
+  });
+
+  get('/2', function(res) {
+    assert.equal(res.statusCode, 200);
+    res.resume();
+    res.on('end', function() {
+      process.nextTick(done);
+    });
+  });
+});