fix possible race condition

Author: nuclearace

Source/SocketEngine.swift

@@ -202,9 +202,12 @@ public final class SocketEngine: NSObject, SocketEnginePollable, SocketEngineWeb
             postSendClose(nil, nil, nil)
         } else {
             // We need to take special care when we're polling that we send it ASAP
-            postWait.append(String(SocketEnginePacketType.Close.rawValue))
-            let req = createRequestForPostWithPostWait()
-            doRequest(req, withCallback: postSendClose)
+            // Also make sure we're on the emitQueue since we're touching postWait
+            dispatch_sync(emitQueue) {
+                self.postWait.append(String(SocketEnginePacketType.Close.rawValue))
+                let req = self.createRequestForPostWithPostWait()
+                self.doRequest(req, withCallback: postSendClose)
+            }
         }
     }
 

Source/SocketIOClient.swift

@@ -214,9 +214,7 @@ public final class SocketIOClient: NSObject, SocketEngineClient, SocketParsable
     }
 
     func didDisconnect(reason: String) {
-        guard status != .Closed else {
-            return
-        }
+        guard status != .Closed else { return }
 
         DefaultSocketLogger.Logger.log("Disconnected: %@", type: logType, args: reason)