#1003828 by rfay: Fixed Drupal.ajaxError may itself throw an exception,...

#1003828 by rfay: Fixed Drupal.ajaxError may itself throw an exception, causing silent 'AJAX Error 0' events

misc/drupal.js

@@ -314,8 +314,22 @@ Drupal.ajaxError = function (xmlhttp, uri) {
   }
   statusCode += "\n" + Drupal.t("Debugging information follows.");
   pathText = "\n" + Drupal.t("Path: !uri", {'!uri': uri} );
-  statusText = xmlhttp.statusText ? ("\n" + Drupal.t("StatusText: !statusText", {'!statusText': $.trim(xmlhttp.statusText)})) : "";
-  responseText = xmlhttp.responseText ? ("\n" + Drupal.t("ResponseText: !responseText", {'!responseText': $.trim(xmlhttp.responseText)})) : "";
+  statusText = '';
+  // In some cases, when statusCode == 0, xmlhttp.statusText may not be defined.
+  // Unfortunately, testing for it with typeof, etc, doesn't seem to catch that
+  // and the test causes an exception. So we need to catch the exception here.
+  try {
+    statusText = "\n" + Drupal.t("StatusText: !statusText", {'!statusText': $.trim(xmlhttp.statusText)});
+  }
+  catch (e) {}
+
+  responseText = '';
+  // Again, we don't have a way to know for sure whether accessing
+  // xmlhttp.responseText is going to throw an exception. So we'll catch it.
+  try {
+    responseText = "\n" + Drupal.t("ResponseText: !responseText", {'!responseText': $.trim(xmlhttp.responseText) } );
+  } catch (e) {}
+
   // Make the responseText more readable by stripping HTML tags and newlines.
   responseText = responseText.replace(/<("[^"]*"|'[^']*'|[^'">])*>/gi,"");
   responseText = responseText.replace(/[\n]+\s+/g,"\n");