32 bit vs. 64 bit HKLs?

Sign-extended?
I would treat that as a bug.

I believe it's by design. See

http://msdn.microsoft.com/library/en-us/dnmidl/html/midl64b.asp

"USER and GDI handles are sign extended 32b values" section.

Hi Igor,

Heh, you stole my thunder on the explanatory text. :-)

It is indeed by design. Though speaking personally, I would have done it a bit differently had it been up to me (obviously it wasn't!).

From the link:

--------------------------------------
USER and GDI handles are sign extended 32b values
To facilitate the porting, a decision has been made that these system handles should stay as 32b values, sign extended to 64b on the 64b platform. That is, the individual handle types are still based on the HANDLE type, which maps to void *, and so the size of the handle is the size of the pointer, i.e. 4 bytes on 32b and 8 bytes on 64b. However, the actual value of the handle on the 64b platform, (i.e. the meaningful bits), fits within the lower 32b, while the upper bits just carry the sign.

This should make it easy to port the majority of the application code. Handling of the special values, like –1, should be fairly transparent. It also should agree nicely with all the cases where the handles had been remoted with the help of the IDL definitions from the public file wtypes.idl. However, care needs to be taken when remoting the handles was done via a DWORD, as the upper long should be properly sign extended on the 64b side. The app should use HandleToLong() and LongToHandle() macros (inline functions) to do the casting right.

So, in general we can have the following situations:

A handle like HWND, HMENU, HPALETTE, HBITMAP etc was sent as its own type (that is specified with HMENU, etc. as the type of the argument) – do nothing, ole32.dll code handles situation as appropriate
A handle was sent as a DWORD – you can:
leave it as such and cast the wire value to handle using LongToHandle()
change the argument to long or LONG_PTR; this is possible in some cases only,
When designing a new interface, in order of preference: use the types themselves, use context handles or use a LONG64 argument to hack through.
Going back to specifics of porting the legacy code, the following system handles fall into the nice 32b compatible category.

The USER handles: HWND, HMENU, HICON, HCURSOR, HDWP, HHOOK, HACCEL, HWINSTA, HDESK, HKL, HMONITOR, HWINEVENTHOOK.

The GDI handles: HBITMAP, HPALETTE, HMETAFILE, HENHMETAFILE, HMETAFILEPICT, HBRUSH, HFONT, HDC, HRGN .
--------------------------------------

Ok, is clear this is cause by signed extension.
But I think is a bug, because the doc sais:
"The low word contains a Language Identifier for the input language and the high word contains a device handle to the physical layout of the keyboard"

Another theory is that the ffff is not because of the sign, but because is Turkish F keyboard.
For the Turkish Q keyboard it will be 0xqqqqqqqqf014041f :-)

Well, that part is a doc bug, at least. :-)

It is clear that you have to convert it from a signed 64bit pointer to a signed 32bit pointer prior to doing the operations on the HKL if you need to do any....

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2010/05/04 The wacky world of WOW64 keyoards, un-leashed, un-locked, un-something-or-other

2008/09/29 What a tangled web we weave when a KLID from an HKL we must receive

2006/08/07 Fixing a bug in the documentation