Bug 1062077 - Report exceptions immediately for non-window globals, and assert that we have a window in ScriptErrorEvent. r=bz

Note that this is a no-op right now, because NS_ScriptErrorReporter currently
relies on nsIScriptContext to get its global, and thus will only ever operate
on window globals. But that will change once we merge this code with that in
xpc::SystemErrorReporter.

dom/base/nsJSEnvironment.cpp

@@ -366,58 +366,57 @@ public:
   {
     nsEventStatus status = nsEventStatus_eIgnore;
     nsPIDOMWindow* win = mReport->mWindow;
+    MOZ_ASSERT(win);
     // First, notify the DOM that we have a script error, but only if
-    // our window is still the current inner, if we're associated with a window.
-    if (mDispatchEvent && (!win || win->IsCurrentInnerWindow())) {
-      nsIDocShell* docShell = win ? win->GetDocShell() : nullptr;
-      if (docShell &&
-          !JSREPORT_IS_WARNING(mReport->mFlags) &&
-          !sHandlingScriptError) {
-        AutoRestore<bool> recursionGuard(sHandlingScriptError);
-        sHandlingScriptError = true;
+    // our window is still the current inner.
+    if (mDispatchEvent && win->IsCurrentInnerWindow() &&
+        win->GetDocShell() && !JSREPORT_IS_WARNING(mReport->mFlags) &&
+        !sHandlingScriptError)
+    {
+      AutoRestore<bool> recursionGuard(sHandlingScriptError);
+      sHandlingScriptError = true;
 
-        nsRefPtr<nsPresContext> presContext;
-        docShell->GetPresContext(getter_AddRefs(presContext));
+      nsRefPtr<nsPresContext> presContext;
+      win->GetDocShell()->GetPresContext(getter_AddRefs(presContext));
 
-        ThreadsafeAutoJSContext cx;
-        RootedDictionary<ErrorEventInit> init(cx);
-        init.mCancelable = true;
-        init.mFilename = mReport->mFileName;
-        init.mBubbles = true;
+      ThreadsafeAutoJSContext cx;
+      RootedDictionary<ErrorEventInit> init(cx);
+      init.mCancelable = true;
+      init.mFilename = mReport->mFileName;
+      init.mBubbles = true;
 
-        nsCOMPtr<nsIScriptObjectPrincipal> sop(do_QueryInterface(win));
-        NS_ENSURE_STATE(sop);
-        nsIPrincipal* p = sop->GetPrincipal();
-        NS_ENSURE_STATE(p);
+      nsCOMPtr<nsIScriptObjectPrincipal> sop(do_QueryInterface(win));
+      NS_ENSURE_STATE(sop);
+      nsIPrincipal* p = sop->GetPrincipal();
+      NS_ENSURE_STATE(p);
 
-        bool sameOrigin = !mOriginPrincipal;
+      bool sameOrigin = !mOriginPrincipal;
 
-        if (p && !sameOrigin) {
-          if (NS_FAILED(p->Subsumes(mOriginPrincipal, &sameOrigin))) {
-            sameOrigin = false;
-          }
+      if (p && !sameOrigin) {
+        if (NS_FAILED(p->Subsumes(mOriginPrincipal, &sameOrigin))) {
+          sameOrigin = false;
         }
-
-        NS_NAMED_LITERAL_STRING(xoriginMsg, "Script error.");
-        if (sameOrigin) {
-          init.mMessage = mReport->mErrorMsg;
-          init.mLineno = mReport->mLineNumber;
-          init.mColno = mReport->mColumn;
-          init.mError = mError;
-        } else {
-          NS_WARNING("Not same origin error!");
-          init.mMessage = xoriginMsg;
-          init.mLineno = 0;
-        }
-
-        nsRefPtr<ErrorEvent> event =
-          ErrorEvent::Constructor(static_cast<nsGlobalWindow*>(win),
-                                  NS_LITERAL_STRING("error"), init);
-        event->SetTrusted(true);
-
-        EventDispatcher::DispatchDOMEvent(win, nullptr, event, presContext,
-                                          &status);
       }
+
+      NS_NAMED_LITERAL_STRING(xoriginMsg, "Script error.");
+      if (sameOrigin) {
+        init.mMessage = mReport->mErrorMsg;
+        init.mLineno = mReport->mLineNumber;
+        init.mColno = mReport->mColumn;
+        init.mError = mError;
+      } else {
+        NS_WARNING("Not same origin error!");
+        init.mMessage = xoriginMsg;
+        init.mLineno = 0;
+      }
+
+      nsRefPtr<ErrorEvent> event =
+        ErrorEvent::Constructor(static_cast<nsGlobalWindow*>(win),
+                                NS_LITERAL_STRING("error"), init);
+      event->SetTrusted(true);
+
+      EventDispatcher::DispatchDOMEvent(win, nullptr, event, presContext,
+                                        &status);
     }
 
     if (status != nsEventStatus_eConsumeNoDefault) {
@@ -465,6 +464,15 @@ NS_ScriptErrorReporter(JSContext *cx,
     nsRefPtr<xpc::ErrorReport> xpcReport = new xpc::ErrorReport();
     xpcReport->Init(report, message, globalObject);
 
+    // If there's no window to fire an event at, report it to the console
+    // directly.
+    if (!xpcReport->mWindow) {
+      xpcReport->LogToConsole();
+      return;
+    }
+
+    // Otherwise, we need to asynchronously invoke onerror before we can decide
+    // whether or not to report the error to the console.
     nsContentUtils::AddScriptRunner(
       new ScriptErrorEvent(JS_GetRuntime(cx),
                            xpcReport,