SHChangeNotifyRegister and windows XP

[Nikos Bozinis]

I've been experimenting with the infamous & undocumented
SHChangeNotifyRegister as described in
http://www.geocities.com/SiliconValley/4942/

I have discovered that when this is used to monitor a pidl _without_ the
SHCNF_NO_PROXY flag then windows XP leaks one window handle per call,
even though SHChangeNotifyDeregister is called to free the handle

the same code works without leaks in all other windows platforms I've
tried (98/NT4/2000). Interestingly, the hidden windows responsible for
the transfer of the shell notification data from the memory mapped file
are called "Shell32HiddenNotfyWnd" in the old OS versions, whereas the
leaky XP version calls these "WorkerW"

The leak is cured when SHCNF_NO_PROXY is specified.

I know I can't be fussy about undocumented features, but I thought that
the shell team should know just in case something went amiss.