Merge branch 'v12.1.3'

* v12.1.3:
  bump version
  Fix #855

Author: nuclearace

Diff for: README.md

@@ -93,7 +93,7 @@ Then import `import SocketIO`.
 ### Carthage
 Add this line to your `Cartfile`:
 ```
-github "socketio/socket.io-client-swift" ~> 12.1.2 # Or latest version
+github "socketio/socket.io-client-swift" ~> 12.1.3 # Or latest version
 ```
 
 Run `carthage update --platform ios,macosx`.
@@ -107,7 +107,7 @@ Create `Podfile` and add `pod 'Socket.IO-Client-Swift'`:
 use_frameworks!
 
 target 'YourApp' do
-    pod 'Socket.IO-Client-Swift', '~> 12.1.2' # Or latest version
+    pod 'Socket.IO-Client-Swift', '~> 12.1.3' # Or latest version
 end
 ```
 

Diff for: Socket.IO-Client-Swift.podspec

@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
   s.name         = "Socket.IO-Client-Swift"
   s.module_name  = "SocketIO"
-  s.version      = "12.1.2"
+  s.version      = "12.1.3"
   s.summary      = "Socket.IO-client for iOS and OS X"
   s.description  = <<-DESC
                    Socket.IO-client for iOS and OS X.
@@ -17,7 +17,7 @@ Pod::Spec.new do |s|
   s.requires_arc = true
   s.source = {
     :git => "https://github.com/socketio/socket.io-client-swift.git",
-    :tag => 'v12.1.2',
+    :tag => 'v12.1.3',
     :submodules => true
   }
   s.pod_target_xcconfig = {

Diff for: Source/SocketIO/Engine/SocketEngine.swift

@@ -563,8 +563,11 @@ public final class SocketEngine : NSObject, URLSessionDelegate, SocketEnginePoll
         pongsMissed += 1
         write("", withType: .ping, withData: [])
 
-        engineQueue.asyncAfter(deadline: DispatchTime.now() + .milliseconds(pingInterval)) {[weak self] in
-            self?.sendPing()
+        engineQueue.asyncAfter(deadline: DispatchTime.now() + .milliseconds(pingInterval)) {[weak self, id = self.sid] in
+            // Make sure not to ping old connections
+            guard let this = self, this.sid == id else { return }
+
+            this.sendPing()
         }
     }