[PATCH 6/6] ole32: Implement MkParseDisplayName.

[Robert Shearman]

Juan Lang wrote:
> +/* find a character from a set in reverse without the string having to be
> null-terminated */
> +static inline WCHAR *memrpbrkW(const WCHAR *ptr, size_t n, const WCHAR
> *accept)
> +{
> +    const WCHAR *end, *ret = NULL;
> +    for (end = ptr + n; ptr < end; ptr++) if (strchrW(accept, *ptr)) ret
> = ptr;
> +    return (WCHAR *)ret;
> +}
>
> Maybe it's because I'm dense and I don't particularly like three levels of
> indent on a single line, but this doesn't seem to do what I'd expect.  The
> for loop doesn't quit when ret is assigned, thus, this will always find
> the last character, from left to right, from accept in ptr, rather than
> the first.
>   

I tested this function so I'm fairly sure it's correct. It's also based 
on the code of several functions merged into one from 
include/wine/unicode.h (including strrchrW). Perhaps it would be better 
to rework the function for efficiency.
I'm pretty sure it does the right thing though, as can be shown in the 
following example:
ptr: "abcdefg", size: 6, accept: "bdg"

end = ptr + 8 (end is "g")
ptr < end = TRUE
strchrW("bdg", 'a') = NULL
ptr++ (ptr is now "bcdefg")
ptr < end = TRUE
strchrW("bdg", 'b') = "bdg"
ret = ptr (ret is now "bcdefg")
ptr++ (ptr is now "cdefghi")
ptr < end = TRUE
strchrW("bdg", 'c') = NULL
ptr++ (ptr is now "defg")
ptr < end = TRUE
strchrW("bdg", 'd') = "dg"
ret = ptr (ret is now "defg")
ptr++ (ptr is now "efg")
ptr < end = TRUE
strchrW("bdg", 'e') = NULL
ptr++ (ptr is now "fg")
ptr < end = TRUE
strchrW("bdg", 'f') = NULL
ptr++ (ptr is now "g")
ptr < end = FALSE
return ret (ret is "defg")

> Don't you mean "ptr < end && !ret"?

I suppose that could be done for safety, but in this case it doesn't a 
matter as I've calculated size using strlenW.

> And in what sense is this "in
> reverse"?
>   

It returns the position of the last character in the input string that 
matches a character in accept.

-- 
Rob Shearman