Today, calling GetOrCreateObjectFromComInstance on a ComWrappers instance with the CreateObjectFlags.Unwrap flag will unwrap a ManagedObjectWrapper from any ComWrappers instance. We propose changing this behavior to only unwrap wrappers from the ComWrappers instance that GetOrCreateObjectFromComInstance was called on.
Currently, the Unwrap flag is the only API that reaches "across" ComWrappers instances, so its behavior is unintuitive. Additionally, we just released an API on ComWrappers called TryGetObject that will unwrap a COM object from any ComWrappers instance.
The existing behavior is blocking #86177.
We see this breaking change as having minimal risk as the only OSS consumer of the API outside of dotnet/runtime is dotnet/winforms, and that usage is already written to expect the new behavior (and would fail with the existing behavior if it was ever hit). This search was done with https://grep.app/search?q=CreateObjectFlags.Unwrap, and a similar search on GitHub's code search showed identical results.
Additionally, since we have ComWrappers.TryGetObject, we believe we have an easy migration path for anyone who is expecting the existing behavior.
Today, calling
GetOrCreateObjectFromComInstanceon aComWrappersinstance with theCreateObjectFlags.Unwrapflag will unwrap a ManagedObjectWrapper from anyComWrappersinstance. We propose changing this behavior to only unwrap wrappers from theComWrappersinstance thatGetOrCreateObjectFromComInstancewas called on.Currently, the
Unwrapflag is the only API that reaches "across" ComWrappers instances, so its behavior is unintuitive. Additionally, we just released an API on ComWrappers calledTryGetObjectthat will unwrap a COM object from anyComWrappersinstance.The existing behavior is blocking #86177.
We see this breaking change as having minimal risk as the only OSS consumer of the API outside of dotnet/runtime is dotnet/winforms, and that usage is already written to expect the new behavior (and would fail with the existing behavior if it was ever hit). This search was done with https://grep.app/search?q=CreateObjectFlags.Unwrap, and a similar search on GitHub's code search showed identical results.
Additionally, since we have
ComWrappers.TryGetObject, we believe we have an easy migration path for anyone who is expecting the existing behavior.