Embedded Windows Media Player loaded in QtWebKit: set volume does not work

when loading this html (html is also here) in the 开发者_如何学运维Qt 4.6 Demo Browser,

pressing "Set Volume = 80" fails without raising an exception.

Notes:

The same html works fine in Chrome and Firefox.

Happens on Windows, but works fine on Mac.

Fails also with Qt 4.7 Beta Demo, and in Arora browser.

Any idea?

---

It is a bug in QtWebKit's treatment of calls to NPAPI plugin: Int32 is treated as double.
I put a patch to fix this.
Replace the contents of the file:
\Qt\2010.02.1\qt\src\3rdparty\webkit\WebCore\bridge\c\c_utility.cpp
by this.