time out requests after 30 seconds

services/sync/modules/dav.js

@@ -133,6 +133,12 @@ DAVCollection.prototype = {
     request.mozBackgroundRequest = true;
     request.open(op, this._baseURL + path, true);
 
+    // time out requests after 30 seconds
+    let cb = function() { request.abort(); };
+    let listener = new Utils.EventListener(cb);
+    let timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
+    timer.initWithCallback(listener, 30000, timer.TYPE_ONE_SHOT);
+
     // Force cache validation
     let channel = request.channel;
     channel = channel.QueryInterface(Ci.nsIRequest);