user32: Remove unneeded casts.

[Andrew Talbot]

Michael Stefaniuc wrote:

> I just stumbled upon those while researching a potential problem for
> which Smatch issued a warning.
> [...]
> @@ -1324,7 +1324,7 @@ HDDEDATA WINAPI DdeAddData(HDDEDATA hData, LPBYTE
> pSrc, DWORD cb, DWORD cbOff)
>      if (new_sz > old_sz)
>      {
>  DdeUnaccessData(hData);
> -     hData = GlobalReAlloc((HGLOBAL)hData, new_sz +
> sizeof(DDE_DATAHANDLE_HEAD),
> +     hData = GlobalReAlloc(hData, new_sz + sizeof(DDE_DATAHANDLE_HEAD),
[...]

Hi,

In general, I have left the casts in where one PVOID-type handle was cast as
another, e.g. HMODULE as HANDLE: I wasn't sure if strict typing might (one
day) be an issue. AFAIK, my only transgressions were when I removed the
casts from the return values of some {Local|Global}Alloc() and family
functions, where they, strictly speaking, return a handle, not a literal
PVOID, so arguably should be cast. For example:

    PSID pSid = (PSID)LocalAlloc(0, cBytes);

Since LocalAlloc() returns a HLOCAL - which just happens to be a PVOID - one
might argue that the cast should remain. As another example of
type-equivalence versus -distinction, DWORD and ULONG are both defined as
unsigned long, but I have currently left them as distinct types, too.

I would be glad for feedback on how type-strict we should be, please.

Thanks,

-- 
Andy.