[PATCH] vbscript: implement case insensitive comparison functionality in InStr

[Jacek Caban]

Signed-off-by: Jacek Caban

---

We should probably handle embedded null bytes, which would require 
avoiding wcsstr, but the patch has the same limitations as existing 
implementation, so it's fine for now.

[Alexandre Julliard]

Dmitry Kislyuk  writes:
>  }else {
> -
>    ret = 0;
> -
>    BSTR lowstr1, lowstr2;
> -
>    lowstr1 = SysAllocString(str1);
> -
>    if(!lowstr1)
> -
>        return E_OUTOFMEMORY;
> -
>    lowstr2 = SysAllocString(str2);
> -
>    if(!lowstr2) {
> -
>        SysFreeString(lowstr1);
> -
>        return E_OUTOFMEMORY;
> -
>    }
> -
> -
>    for(ptr = lowstr1; *ptr; ptr++)
> -
>        *ptr = towlower(*ptr);
> -
>    for(ptr = lowstr2; *ptr; ptr++)
> -
>        *ptr = towlower(*ptr);
> -
> -
>    ptr = wcsstr(lowstr1+start, lowstr2);
> -
>    ret = ptr ? ptr-lowstr1+1 : 0;
> -
>    SysFreeString(lowstr1);
> -
>    SysFreeString(lowstr2);

This looks very inefficient. You should be able to use wcsnicmp() or
something similar, and avoid duplicating the strings and lower-casing
them char by char.