TLS sockets should not be writable after 'end'

Closes GH-694.

lib/http.js

@@ -1282,7 +1282,8 @@ Agent.prototype._establishNewConnection = function() {
       // but outgoingFlush instead.
       if (!req.shouldKeepAlive) {
         debug('AGENT socket.end()');
-        socket.end();
+        if (socket.writable) socket.end();
+        assert(!socket.writable);
       } else {
         debug('AGENT socket keep-alive');
       }

lib/tls.js

@@ -553,6 +553,9 @@ SecurePair.prototype._destroy = function() {
     this._ssl.close();
     this._ssl = null;
 
+    self.encrypted.writable = self.encrypted.readable = false;
+    self.cleartext.writable = self.cleartext.readable = false;
+
     process.nextTick(function() {
       self.encrypted.emit('end');
       if (self.encrypted.onend) self.encrypted.onend();

test/disabled/test-https-loop-to-google.js

@@ -0,0 +1,31 @@
+// Failing test for https
+
+// Will fail with "socket hang up" for 4 out of 10 requests
+// Tested on node 0.5.0-pre commit 9851574
+
+
+var https = require('https');
+
+for(var i = 0; i < 10; ++i)
+{
+  https.get(
+  {
+    host: 'www.google.com',
+    path: '/accounts/o8/id',
+    port: 443,
+  }, function(res)
+  {
+    var data = ''; 
+    res.on('data', function(chunk)
+    {   
+      data += chunk;
+    }); 
+    res.on('end', function()
+    {   
+      console.log(res.statusCode);
+    }); 
+  }).on('error', function(error)
+  {
+    console.log(error);
+  }); 
+}

test/simple/test-tls-securepair-server.js

@@ -52,8 +52,6 @@ var server = net.createServer(function(socket) {
 
   socket.on('end', function() {
     log('socket end');
-    pair.cleartext.write('goodbye\r\n');
-    pair.cleartext.end();
   });
 
   pair.cleartext.on('error', function(err) {