Bug 1836127 - Nullable union used as callback arguments needs to be actually declared; r=peterv

Differential Revision: https://phabricator.services.mozilla.com/D176127

dom/bindings/Codegen.py

@@ -1363,15 +1363,21 @@ class CGHeaders(CGWrapper):
         bindingHeaders = set()
         declareIncludes = set(declareIncludes)
 
-        def addHeadersForType(typeAndPossibleDictionary):
+        def addHeadersForType(typeAndPossibleOriginType):
             """
-            Add the relevant headers for this type.  We use dictionary, if
+            Add the relevant headers for this type.  We use its origin type, if
             passed, to decide what to do with interface types.
             """
-            t, dictionary = typeAndPossibleDictionary
+            t, originType = typeAndPossibleOriginType
+            isFromDictionary = originType and originType.isDictionary()
+            isFromCallback = originType and originType.isCallback()
             # Dictionaries have members that need to be actually
             # declared, not just forward-declared.
-            if dictionary:
+            # Callbacks have nullable union arguments that need to be actually
+            # declared, not just forward-declared.
+            if isFromDictionary:
+                headerSet = declareIncludes
+            elif isFromCallback and t.nullable() and t.isUnion():
                 headerSet = declareIncludes
             else:
                 headerSet = bindingHeaders
@@ -1446,13 +1452,13 @@ class CGHeaders(CGWrapper):
             elif unrolled.isPrimitive():
                 bindingHeaders.add("mozilla/dom/PrimitiveConversions.h")
             elif unrolled.isRecord():
-                if dictionary or jsImplementedDescriptors:
+                if isFromDictionary or jsImplementedDescriptors:
                     declareIncludes.add("mozilla/dom/Record.h")
                 else:
                     bindingHeaders.add("mozilla/dom/Record.h")
                 # Also add headers for the type the record is
                 # parametrized over, if needed.
-                addHeadersForType((t.inner, dictionary))
+                addHeadersForType((t.inner, originType if isFromDictionary else None))
 
         for t in getAllTypes(
             descriptors + callbackDescriptors, dictionaries, callbacks

dom/bindings/Configuration.py

@@ -1083,7 +1083,7 @@ def getAllTypes(descriptors, dictionaries, callbacks):
             yield (t, dictionary)
     for callback in callbacks:
         for t in getTypesFromCallback(callback):
-            yield (t, None)
+            yield (t, callback)
 
 
 # For sync value iterators, we use default array implementation, for async

dom/bindings/test/TestBindingHeader.h

@@ -24,6 +24,7 @@ namespace mozilla {
 namespace dom {
 class DocGroup;
 class TestExternalInterface;
+class TestUnionArguments;
 class Promise;
 }  // namespace dom
 }  // namespace mozilla

dom/bindings/test/TestCallback.webidl

@@ -0,0 +1,10 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+callback TestUnionArguments = undefined((DOMString or long) arg1,
+                                        (DOMString or long)? arg2,
+                                        optional (DOMString or long) arg3,
+                                        optional (DOMString or long)? arg4);

dom/bindings/test/TestCodeGen.webidl

@@ -126,10 +126,6 @@ callback TestOptionalArguments = undefined(optional DOMString aString,
                                            optional TestInterface? anInterface,
                                            optional TestInterface anotherInterface,
                                            optional long aLong);
-callback TestUnionArguments = undefined((DOMString or long) arg1,
-                                        (DOMString or long)? arg2,
-                                        optional (DOMString or long) arg3,
-                                        optional (DOMString or long)? arg4);
 // Callback constructor return value tests
 callback constructor TestUndefinedConstruction = undefined(TestDictionaryTypedef arg);
 callback constructor TestIntegerConstruction = unsigned long();

dom/bindings/test/moz.build

@@ -17,6 +17,7 @@ MOCHITEST_MANIFESTS += ["mochitest.ini"]
 MOCHITEST_CHROME_MANIFESTS += ["chrome.ini"]
 
 TEST_WEBIDL_FILES += [
+    "TestCallback.webidl",
     "TestDictionary.webidl",
     "TestJSImplInheritanceGen.webidl",
     "TestTypedef.webidl",