Bug 619162: default resource success is false; retry once. r=philiKON

services/sync/modules/resource.js

@@ -230,7 +230,7 @@ AsyncResource.prototype = {
     // Set some default values in-case there's no response header
     let headers = {};
     let status = 0;
-    let success = true;
+    let success = false;
     try {
       // Read out the response headers if available
       channel.visitResponseHeaders({
@@ -373,7 +373,13 @@ Resource.prototype = {
   //
   // Perform an asynchronous HTTP GET for this resource.
   get: function Res_get() {
-    return this._request("GET");
+    let response = this._request("GET");
+    if (response.status == 0) {
+      // This must be an erroneously cached response. Try again.
+      this._log.debug("Status 0 in Resource.get: retrying once.");
+      response = this._request("GET");
+    }
+    return response;
   },
 
   // ** {{{ Resource.put }}} **

services/sync/modules/service.js

@@ -673,6 +673,7 @@ WeaveSvc.prototype = {
   _fetchInfo: function _fetchInfo(url, logout) {
     let infoURL = url || this.infoURL;
     
+    this._log.trace("In _fetchInfo: " + infoURL);
     let info = new Resource(infoURL).get();
     if (!info.success) {
       if (info.status == 401) {

services/sync/tests/unit/test_resource.js

@@ -137,6 +137,36 @@ function server_headers(metadata, response) {
   response.bodyOutputStream.write(body, body.length);
 }
 
+/*
+ * Utility to allow us to fake a bad cached response within AsyncResource.
+ * Swap out the _onComplete handler, pretending to throw before setting
+ * status to non-zero. Return an empty response.
+ *
+ * This should prompt Res_get to retry once.
+ *
+ * Set FAKE_ZERO_COUNTER accordingly.
+ */
+let FAKE_ZERO_COUNTER = 0;
+function fake_status_failure() {
+  _("Switching in status-0 _onComplete handler.");
+  let c = AsyncResource.prototype._onComplete;
+  AsyncResource.prototype._onComplete = function(error, data) {
+    if (FAKE_ZERO_COUNTER > 0) {
+      _("Faking status 0 return...");
+      FAKE_ZERO_COUNTER--;
+      let ret = new String(data);
+      ret.headers = {};
+      ret.status = 0;
+      ret.success = false;
+      Utils.lazy2(ret, "obj", function() JSON.parse(ret));
+
+      this._callback(null, ret);
+    }
+    else {
+      c.apply(this, arguments);
+    }
+  };
+}
 
 function run_test() {
   do_test_pending();
@@ -412,5 +442,35 @@ function run_test() {
   do_check_eq(content.status, 401);
   do_check_false(content.success);
 
+  // Faking problems.
+  fake_status_failure();
+
+  // POST doesn't do our inner retry, so we get a status 0.
+  FAKE_ZERO_COUNTER = 1;
+  let res14 = new Resource("http://localhost:8080/open");
+  content = res14.post("hello");
+  do_check_eq(content.status, 0);
+  do_check_false(content.success);
+
+  // And now we succeed...
+  let res15 = new Resource("http://localhost:8080/open");
+  content = res15.post("hello");
+  do_check_eq(content.status, 405);
+  do_check_false(content.success);
+
+  // Now check that GET silent failures get retried.
+  FAKE_ZERO_COUNTER = 1;
+  let res16 = new Resource("http://localhost:8080/open");
+  content = res16.get();
+  do_check_eq(content.status, 200);
+  do_check_true(content.success);
+
+  // ... but only once.
+  FAKE_ZERO_COUNTER = 2;
+  let res17 = new Resource("http://localhost:8080/open");
+  content = res17.get();
+  do_check_eq(content.status, 0);
+  do_check_false(content.success);
+
   server.stop(do_test_finished);
 }