Backed out changeset 30075641dc6f (bug 1818576) for causing leaks. CLOSED TREE

dom/streams/Transferable.cpp

@@ -809,13 +809,7 @@ MOZ_CAN_RUN_SCRIPT static void SetUpCrossRealmTransformReadable(
 bool ReadableStream::Transfer(JSContext* aCx, UniqueMessagePortId& aPortId) {
   // Step 1: If ! IsReadableStreamLocked(value) is true, throw a
   // "DataCloneError" DOMException.
-  // (Implemented in StructuredCloneHolder::CustomCanTransferHandler, but double
-  // check here as the state might have changed in case this ReadableStream is
-  // created by a TransferStream and being transferred together with the
-  // parent.)
-  if (IsReadableStreamLocked(this)) {
-    return false;
-  }
+  // (Implemented in StructuredCloneHolder::CustomCanTransferHandler)
 
   // Step 2: Let port1 be a new MessagePort in the current Realm.
   // Step 3: Let port2 be a new MessagePort in the current Realm.
@@ -901,13 +895,7 @@ bool ReadableStream::ReceiveTransfer(
 bool WritableStream::Transfer(JSContext* aCx, UniqueMessagePortId& aPortId) {
   // Step 1: If ! IsWritableStreamLocked(value) is true, throw a
   // "DataCloneError" DOMException.
-  // (Implemented in StructuredCloneHolder::CustomCanTransferHandler, but double
-  // check here as the state might have changed in case this WritableStream is
-  // created by a TransferStream and being transferred together with the
-  // parent.)
-  if (IsWritableStreamLocked(this)) {
-    return false;
-  }
+  // (Implemented in StructuredCloneHolder::CustomCanTransferHandler)
 
   // Step 2: Let port1 be a new MessagePort in the current Realm.
   // Step 3: Let port2 be a new MessagePort in the current Realm.
@@ -998,13 +986,7 @@ bool TransformStream::Transfer(JSContext* aCx, UniqueMessagePortId& aPortId1,
   // "DataCloneError" DOMException.
   // Step 4: If ! IsWritableStreamLocked(writable) is true, throw a
   // "DataCloneError" DOMException.
-  // (Implemented in StructuredCloneHolder::CustomCanTransferHandler, but double
-  // check here as the state might have changed by
-  // Readable/WritableStream::Transfer in case the stream members of this
-  // TransformStream are being transferred together.)
-  if (IsReadableStreamLocked(mReadable) || IsWritableStreamLocked(mWritable)) {
-    return false;
-  }
+  // (Implemented in StructuredCloneHolder::CustomCanTransferHandler)
 
   // Step 5: Set dataHolder.[[readable]] to !
   // StructuredSerializeWithTransfer(readable, « readable »).

testing/web-platform/tests/streams/transferable/transform-stream-members.any.js

@@ -1,16 +0,0 @@
-const combinations = [
-  (t => [t, t.readable])(new TransformStream()),
-  (t => [t.readable, t])(new TransformStream()),
-  (t => [t, t.writable])(new TransformStream()),
-  (t => [t.writable, t])(new TransformStream()),
-];
-
-for (const combination of combinations) {
-  test(() => {
-    assert_throws_dom(
-      "DataCloneError",
-      () => structuredClone(combination, { transfer: combination }),
-      "structuredClone should throw"
-    );
-  }, `Transferring ${combination} should fail`);
-}