Re: [whatwg/streams] Support transferable streams (postMessage) (#1053)

@ricea commented on this pull request.



> +
+ <p class="note">As we are already in an errored state when this abstract operation is performed, we
+ cannot handle further errors, so we just discard them.</p>
+
+</div>
+
+<div algorithm>
+ <dfn abstract-op lt="SetUpCrossRealmTransformReadable">SetUpCrossRealmTransformReadable(|stream|,
+ |port|)</dfn> performs the following steps:
+
+ 1. Perform ! [$InitializeReadableStream$](|stream|).
+ 1. Let |controller| be a [=new=] {{ReadableStreamDefaultController}}.
+ 1. Let |backpressurePromise| be [=a new promise=].
+ 1. Add a handler for |port|'s {{MessagePort/message}} event with the following steps:
+  1. Let |data| be the data of the message.
+  1. If ! [$Type$](|data|) is not Object, return.

The other realm can be hostile. I thought about adding a note about the security concerns, but I'm not sure there's a concept of a "compromised agent cluster" in spec-land, so I couldn't think of a way to phrase it.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/whatwg/streams/pull/1053#discussion_r452546100