Bug 1107592 part 2. Allow chrome JS to directly throw content DOMExceptions that will propagate out to the web script. r=peterv

dom/bindings/BindingUtils.cpp

@@ -34,6 +34,8 @@
 #include "mozilla/dom/ScriptSettings.h"
 #include "mozilla/dom/DOMError.h"
 #include "mozilla/dom/DOMErrorBinding.h"
+#include "mozilla/dom/DOMException.h"
+#include "mozilla/dom/DOMExceptionBinding.h"
 #include "mozilla/dom/ElementBinding.h"
 #include "mozilla/dom/HTMLObjectElement.h"
 #include "mozilla/dom/HTMLObjectElementBinding.h"
@@ -216,6 +218,10 @@ ErrorResult::ReportJSException(JSContext* cx)
   // If JS_WrapValue failed, not much we can do about it...  No matter
   // what, go ahead and unroot mJSException.
   js::RemoveRawValueRoot(cx, &mJSException);
+
+  // We no longer have a useful exception but we do want to signal that an error
+  // occured.
+  mResult = NS_ERROR_FAILURE;
 }
 
 void
@@ -224,15 +230,52 @@ ErrorResult::ReportJSExceptionFromJSImplementation(JSContext* aCx)
   MOZ_ASSERT(!mMightHaveUnreportedJSException,
              "Why didn't you tell us you planned to handle JS exceptions?");
 
+  dom::DOMException* domException;
+  nsresult rv =
+    UNWRAP_OBJECT(DOMException, &mJSException.toObject(), domException);
+  if (NS_SUCCEEDED(rv)) {
+    // We actually have to create a new DOMException object, because the one we
+    // have has a stack that includes the chrome code that threw it, and in
+    // particular has the wrong file/line/column information.
+    nsString message;
+    domException->GetMessageMoz(message);
+    nsString name;
+    domException->GetName(name);
+    nsRefPtr<dom::DOMException> newException =
+      new dom::DOMException(nsresult(domException->Result()),
+                            NS_ConvertUTF16toUTF8(message),
+                            NS_ConvertUTF16toUTF8(name),
+                            domException->Code());
+    JS::Rooted<JS::Value> reflector(aCx);
+    if (!GetOrCreateDOMReflector(aCx, newException, &reflector)) {
+      // Well, that threw _an_ exception.  Let's forget ours.  We can just
+      // unroot and not change the value, since mJSException is completely
+      // ignored if mResult is not NS_ERROR_DOM_JS_EXCEPTION and we plan to
+      // change mResult to a different value.
+      js::RemoveRawValueRoot(aCx, &mJSException);
+
+      // We no longer have a useful exception but we do want to signal that an
+      // error occured.
+      mResult = NS_ERROR_FAILURE;
+
+      // But do make sure to not ReportJSException here, since we don't have one.
+      return;
+    }
+
+    mJSException = reflector;
+    ReportJSException(aCx);
+    return;
+  }
+
   dom::DOMError* domError;
-  nsresult rv = UNWRAP_OBJECT(DOMError, &mJSException.toObject(), domError);
+  rv = UNWRAP_OBJECT(DOMError, &mJSException.toObject(), domError);
   if (NS_FAILED(rv)) {
-    // Unwrapping really shouldn't fail here, if mExceptionHandling is set to
+    // Unwrapping really shouldn't fail here: if mExceptionHandling is set to
     // eRethrowContentExceptions then the CallSetup destructor only stores an
-    // exception if it unwraps to DOMError. If we reach this then either
-    // mExceptionHandling wasn't set to eRethrowContentExceptions and we
-    // shouldn't be calling ReportJSExceptionFromJSImplementation or something
-    // went really wrong.
+    // exception if it unwraps to DOMError or DOMException. If we reach this
+    // then either mExceptionHandling wasn't set to eRethrowContentExceptions
+    // and we shouldn't be calling ReportJSExceptionFromJSImplementation or
+    // something went really wrong.
     NS_RUNTIMEABORT("We stored a non-DOMError exception!");
   }
 

dom/bindings/CallbackObject.cpp

@@ -8,6 +8,8 @@
 #include "mozilla/dom/BindingUtils.h"
 #include "mozilla/dom/DOMError.h"
 #include "mozilla/dom/DOMErrorBinding.h"
+#include "mozilla/dom/DOMException.h"
+#include "mozilla/dom/DOMExceptionBinding.h"
 #include "jsfriendapi.h"
 #include "nsIScriptGlobalObject.h"
 #include "nsIXPConnect.h"
@@ -190,8 +192,8 @@ CallbackObject::CallSetup::ShouldRethrowException(JS::Handle<JS::Value> aExcepti
   MOZ_ASSERT(mExceptionHandling == eRethrowContentExceptions);
 
   // For eRethrowContentExceptions we only want to throw an exception if the
-  // object that was thrown is a DOMError object in the caller compartment
-  // (which we stored in mCompartment).
+  // object that was thrown is a DOMError or DOMException object in the caller
+  // compartment (which we stored in mCompartment).
 
   if (!aException.isObject()) {
     return false;
@@ -204,7 +206,9 @@ CallbackObject::CallSetup::ShouldRethrowException(JS::Handle<JS::Value> aExcepti
   }
 
   DOMError* domError;
-  return NS_SUCCEEDED(UNWRAP_OBJECT(DOMError, obj, domError));
+  DOMException* domException;
+  return NS_SUCCEEDED(UNWRAP_OBJECT(DOMError, obj, domError)) ||
+         NS_SUCCEEDED(UNWRAP_OBJECT(DOMException, obj, domException));
 }
 
 CallbackObject::CallSetup::~CallSetup()

dom/bindings/CallbackObject.h

@@ -85,8 +85,8 @@ public:
     // Report any exception and don't throw it to the caller code.
     eReportExceptions,
     // Throw an exception to the caller code if the thrown exception is a
-    // binding object for a DOMError from the caller's scope, otherwise report
-    // it.
+    // binding object for a DOMError or DOMException from the caller's scope,
+    // otherwise report it.
     eRethrowContentExceptions,
     // Throw any exception to the caller code.
     eRethrowExceptions

dom/bindings/test/TestInterfaceJS.js

@@ -14,7 +14,10 @@ function TestInterfaceJS(anyArg, objectArg) {}
 TestInterfaceJS.prototype = {
   classID: Components.ID("{2ac4e026-cf25-47d5-b067-78d553c3cad8}"),
   contractID: "@mozilla.org/dom/test-interface-js;1",
-  QueryInterface: XPCOMUtils.generateQI([Ci.nsISupports]),
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsISupports,
+                                         Ci.nsIDOMGlobalPropertyInitializer]),
+
+  init: function(win) { this._win = win; },
 
   __init: function (anyArg, objectArg, dictionaryArg) {
     this._anyAttr = undefined;
@@ -59,6 +62,15 @@ TestInterfaceJS.prototype = {
 
   testSequenceOverload: function(arg) {},
   testSequenceUnion: function(arg) {},
+
+  testThrowDOMError: function() {
+    throw new this._win.DOMError("NotSupportedError", "We are a DOMError");
+  },
+
+  testThrowDOMException: function() {
+    throw new this._win.DOMException("We are a DOMException",
+                                     "NotSupportedError");
+  },
 };
 
 this.NSGetFactory = XPCOMUtils.generateNSGetFactory([TestInterfaceJS])

dom/bindings/test/mochitest.ini

@@ -53,3 +53,5 @@ skip-if = debug == false
 [test_traceProtos.html]
 [test_sequence_detection.html]
 skip-if = debug == false
+[test_exception_options_from_jsimplemented.html]
+skip-if = debug == false

dom/bindings/test/test_exception_options_from_jsimplemented.html

@@ -0,0 +1,73 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1107592
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Test for Bug 1107592</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+  <script type="application/javascript">
+
+  /** Test for Bug 1107592 **/
+
+  SimpleTest.waitForExplicitFinish();
+
+  function doTest() {
+    var t = new TestInterfaceJS();
+    try {
+      t.testThrowDOMError();
+    } catch (e) {
+      ok(e instanceof Error, "Should have an Error here");
+      ok(!(e instanceof DOMException), "Should not have DOMException here");
+      ok(!("code" in e), "Should not have a 'code' property");
+      ise(e.name, "Error", "Should not have an interesting name here");
+      ise(e.message, "We are a DOMError", "Should have the right message");
+      ise(e.stack,
+          "doTest@http://mochi.test:8888/tests/dom/bindings/test/test_exception_options_from_jsimplemented.html:20:7\n",
+          "Exception stack should still only show our code");
+      ise(e.fileName,
+          "http://mochi.test:8888/tests/dom/bindings/test/test_exception_options_from_jsimplemented.html",
+          "Should have the right file name");
+      ise(e.lineNumber, 20, "Should have the right line number");
+      ise(e.columnNumber, 6, "Should have the right column number");
+    }
+
+    try {
+      t.testThrowDOMException();
+    } catch (e) {
+      ok(e instanceof Error, "Should also have an Error here");
+      ok(e instanceof DOMException, "Should have DOMException here");
+      ise(e.name, "NotSupportedError", "Should have the right name here");
+      ise(e.message, "We are a DOMException",
+          "Should also have the right message");
+      ise(e.code, DOMException.NOT_SUPPORTED_ERR,
+          "Should have the right 'code'");
+      ise(e.stack,
+          "doTest@http://mochi.test:8888/tests/dom/bindings/test/test_exception_options_from_jsimplemented.html:38:6\n",
+          "Exception stack should still only show our code");
+      ise(e.filename,
+          "http://mochi.test:8888/tests/dom/bindings/test/test_exception_options_from_jsimplemented.html",
+          "Should still have the right file name");
+      ise(e.lineNumber, 38, "Should still have the right line number");
+      todo_is(e.columnNumber, 6,
+              "No column number support for DOMException yet");
+    }
+    SimpleTest.finish();
+  }
+
+  SpecialPowers.pushPrefEnv({set: [['dom.expose_test_interfaces', true]]},
+                            doTest);
+  </script>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1107592">Mozilla Bug 1107592</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+
+</div>
+<pre id="test">
+</pre>
+</body>
+</html>

dom/webidl/TestInterfaceJS.webidl

@@ -48,4 +48,11 @@ interface TestInterfaceJS {
   void testSequenceOverload(DOMString arg);
 
   void testSequenceUnion((sequence<DOMString> or DOMString) arg);
+
+  // Tests for exception-throwing behavior
+  [Throws]
+  void testThrowDOMError();
+
+  [Throws]
+  void testThrowDOMException();
 };