Fix issue with iframe targetWindow not being immediately available.

src/General/lib/connection.class

@@ -2,11 +2,14 @@ class Connection
   constructor: (@target, @origin, @cb={}) ->
     $.on window, 'message', @onMessage
 
+  targetWindow: ->
+    @target.contentWindow or @target
+
   send: (data) =>
-    @target.postMessage "#{g.NAMESPACE}#{JSON.stringify data}", @origin
+    @targetWindow().postMessage "#{g.NAMESPACE}#{JSON.stringify data}", @origin
 
   onMessage: (e) =>
-    return unless e.source is @target and
+    return unless e.source is @targetWindow() and
       e.origin is @origin and
       typeof e.data is 'string' and
       e.data[...g.NAMESPACE.length] is g.NAMESPACE

src/Posting/Captcha.noscript.coffee

@@ -98,7 +98,7 @@ Captcha.noscript =
         id: 'qr-captcha-iframe'
         src: @iframeURL()
       $.add QR.nodes.el, @nodes.iframe
-      @conn.target = @nodes.iframe.contentWindow
+      @conn.target = @nodes.iframe
     else if !@occupied or force
       @nodes.iframe.src = @iframeURL()
     @occupied = true

src/Posting/Captcha.v2.coffee

@@ -96,7 +96,7 @@ Captcha.v2 =
       id: 'qr-captcha-iframe'
       src: @noscriptURL()
     $.add @nodes.container, iframe
-    @conn.target = iframe.contentWindow
+    @conn.target = iframe
 
   setupJS: ->
     $.globalEval '''