Fixes cross domain XHR on IE8/9

lib/transports/xhr-polling.js

@@ -64,7 +64,7 @@
 
     function stateChange () {
       if (this.readyState == 4) {
-        this.onreadystatechange = this.onload = empty;
+        this.onreadystatechange = empty;
 
         if (this.status == 200) {
           self.onData(this.responseText);
@@ -73,13 +73,21 @@
           self.onClose();
         }
       }
-    }
+    };
+
+    function onload () {
+      this.onload = empty;
+      self.onData(this.responseText);
+      self.get();
+    };
 
     this.xhr = this.request();
 
     if (window.XDomainRequest && this.xhr instanceof XDomainRequest) {
-      this.xhr.onload = stateChange;
-      this.xhr.onerror = function (e) { self.onError(e); };
+      this.xhr.onload = onload;
+      this.xhr.onerror = function (e) {
+        self.onError(e);
+      };
     } else {
       this.xhr.onreadystatechange = stateChange;
     }

lib/transports/xhr.js

@@ -103,7 +103,7 @@
 
     function stateChange () {
       if (this.readyState == 4) {
-        this.onreadystatechange = this.onload = empty;
+        this.onreadystatechange = empty;
         self.posting = false;
 
         if (this.status == 200){
@@ -114,10 +114,19 @@
       }
     }
 
+    function onload () {
+      this.onload = empty;
+      self.posting = false;
+      self.checkSend();
+    };
+
     this.sendXHR = this.request('POST');
 
     if (window.XDomainRequest && this.xhr instanceof XDomainRequest) {
-      this.sendXHR.onload = stateChange;
+      this.sendXHR.onload = onload;
+      this.sendXHR.onerror = function (e) {
+        self.onError(e);
+      };
     } else {
       this.sendXHR.onreadystatechange = stateChange;
     }
@@ -171,7 +180,9 @@
         req.setRequestHeader('Content-type', 'text/plain');
       } else {
         // XDomainRequest
-        req.contentType = 'text/plain';
+        try {
+          req.contentType = 'text/plain';
+        } catch (e) {}
       }
     }