4 files changed, 20 insertions, 38 deletions

diff --git a/dom/fetch/Request.cpp b/dom/fetch/Request.cpp
index d3836cda1..7ca5b43c4 100644
--- a/dom/fetch/Request.cpp
+++ b/dom/fetch/Request.cpp
@@ -338,8 +338,7 @@ Request::Constructor(const GlobalObject& aGlobal,
 
   if (mode == RequestMode::Navigate ||
       (aInit.IsAnyMemberPresent() && request->Mode() == RequestMode::Navigate)) {
-    aRv.ThrowTypeError<MSG_INVALID_REQUEST_MODE>(NS_LITERAL_STRING("navigate"));
-    return nullptr;
+    mode = RequestMode::Same_origin;
   }
 
   if (aInit.IsAnyMemberPresent()) {
@@ -374,11 +373,7 @@ Request::Constructor(const GlobalObject& aGlobal,
             nsresult rv = principal->CheckMayLoad(uri, /* report */ false,
                                                   /* allowIfInheritsPrincipal */ false);
             if (NS_FAILED(rv)) {
-              nsAutoCString globalOrigin;
-              principal->GetOrigin(globalOrigin);
-              aRv.ThrowTypeError<MSG_CROSS_ORIGIN_REFERRER_URL>(referrer,
-                                                                NS_ConvertUTF8toUTF16(globalOrigin));
-              return nullptr;
+              referrerURL.AssignLiteral(kFETCH_CLIENT_REFERRER_STR);
             }
           }
         }
@@ -403,11 +398,10 @@ Request::Constructor(const GlobalObject& aGlobal,
           // this work in a single sync loop.
           RefPtr<ReferrerSameOriginChecker> checker =
             new ReferrerSameOriginChecker(worker, referrerURL, rv);
-          checker->Dispatch(Terminating, aRv);
-          if (aRv.Failed() || NS_FAILED(rv)) {
-            aRv.ThrowTypeError<MSG_CROSS_ORIGIN_REFERRER_URL>(referrer,
-                                                              worker->GetLocationInfo().mOrigin);
-            return nullptr;
+          IgnoredErrorResult error;
+          checker->Dispatch(Terminating, error);
+          if (error.Failed() || NS_FAILED(rv)) {
+            referrerURL.AssignLiteral(kFETCH_CLIENT_REFERRER_STR);
           }
         }
       }
diff --git a/dom/tests/mochitest/fetch/test_request.js b/dom/tests/mochitest/fetch/test_request.js
index 5be361a46..405767b50 100644
--- a/dom/tests/mochitest/fetch/test_request.js
+++ b/dom/tests/mochitest/fetch/test_request.js
@@ -152,12 +152,9 @@ function testHeaderGuard() {
 }
 
 function testMode() {
-  try {
-    var req = new Request("http://example.com", {mode: "navigate"});
-    ok(false, "Creating a Request with navigate RequestMode should throw a TypeError");
-  } catch(e) {
-    is(e.name, "TypeError", "Creating a Request with navigate RequestMode should throw a TypeError");
-  }
+  var req = new Request("http://example.com", {mode: "navigate"});
+  ok(true, "Creating a Request with navigate RequestMode should not throw.");
+  is(req.mode, "same-origin", "Request mode becomes same-origin");
 }
 
 function testMethod() {
diff --git a/dom/workers/test/serviceworkers/fetch_event_worker.js b/dom/workers/test/serviceworkers/fetch_event_worker.js
index 1caef71e8..895128e2c 100644
--- a/dom/workers/test/serviceworkers/fetch_event_worker.js
+++ b/dom/workers/test/serviceworkers/fetch_event_worker.js
@@ -148,28 +148,21 @@ onfetch = function(ev) {
   }
 
   else if (ev.request.url.includes("navigate.html")) {
-    var navigateModeCorrectlyChecked = false;
     var requests = [ // should not throw
       new Request(ev.request),
       new Request(ev.request, undefined),
       new Request(ev.request, null),
       new Request(ev.request, {}),
       new Request(ev.request, {someUnrelatedProperty: 42}),
+      new Request(ev.request, {method: "GET"}),
     ];
-    try {
-      var request3 = new Request(ev.request, {method: "GET"}); // should throw
-    } catch(e) {
-      navigateModeCorrectlyChecked = requests[0].mode == "navigate";
-    }
-    if (navigateModeCorrectlyChecked) {
-      ev.respondWith(Promise.resolve(
-        new Response("<script>window.frameElement.test_result = true;</script>", {
-          headers : {
-            "Content-Type": "text/html"
-          }
-        })
-      ));
-    }
+    ev.respondWith(Promise.resolve(
+      new Response("<script>window.frameElement.test_result = true;</script>", {
+        headers : {
+          "Content-Type": "text/html"
+        }
+      })
+    ));
   }
 
   else if (ev.request.url.includes("nonexistent_worker_script.js")) {
diff --git a/dom/xhr/XMLHttpRequestWorker.cpp b/dom/xhr/XMLHttpRequestWorker.cpp
index b5f853a50..c9e892f26 100644
--- a/dom/xhr/XMLHttpRequestWorker.cpp
+++ b/dom/xhr/XMLHttpRequestWorker.cpp
@@ -1633,12 +1633,10 @@ XMLHttpRequestWorker::ReleaseProxy(ReleaseType aType)
         new SyncTeardownRunnable(mWorkerPrivate, mProxy);
       mProxy = nullptr;
 
-      ErrorResult forAssertionsOnly;
+      IgnoredErrorResult forAssertionsOnly;
       // This runnable _must_ be executed.
-      runnable->Dispatch(Killing, forAssertionsOnly);
-      if (forAssertionsOnly.Failed()) {
-        NS_ERROR("Failed to dispatch teardown runnable!");
-      }
+      runnable->Dispatch(Dead, forAssertionsOnly);
+      MOZ_DIAGNOSTIC_ASSERT(!forAssertionsOnly.Failed());
     }
   }
 }