Bug 27419 – Storing a reference to WorkerContext.postMessage() and calling it later yields a TypeError

• Component: WebCore JavaScript
• Status: RESOLVED FIXED

[Andrew Wilson]

There are a number of functions defined at global scope in WorkerContext - for example, setTimeout() and postMessage() are both defined in the worker global context.

It's perfectly valid for worker code to do this:

postMessage("hello");

However, if the worker code does this instead, it gets a TypeError:

var saved = postMessage;
saved("hello");

[Andrew Wilson]

The test case works in Chromium, so it's somewhere in the JSC bindings.

[Andrew Wilson]

On a related note, the following line of code from Worker Context results in a TypeError also:

postMessage.call(null, "foobar");

[Andrew Wilson]

Created attachment 33094 [details]
test case

test case that shows this problem (passes on FF/Chrome, fails on Safari 4)

[Andrew Wilson]

Created attachment 33209 [details]
proposed patch

This is dependent on 27420 as it relies on the IsWorkerContext attribute added in that patch.

[Adam Barth]

Comment on attachment 33209 [details]
proposed patch

Awesome.  Thanks for the patch.

[Dmitry Titov]

assingning to me for landing

[Dmitry Titov]

Landed: http://trac.webkit.org/changeset/46371