[1/3] scrrun: Implement filesys_DriveExists.

[Nikolay Sivov]

On 15.10.2015 13:56, Joachim Priesner wrote:
> +    if (!pfExists) return E_POINTER;
> +    *pfExists = VARIANT_FALSE;
> +    len = SysStringLen(DriveSpec);
> +    if (len >= 1 && DriveSpec[0] >= 'A' && DriveSpec[0] <= 'Z'
> +            && (len < 2 || DriveSpec[1] == ':')
> +            && (len < 3 || DriveSpec[2] == '\\')) {
> +        WCHAR root[] = {toupperW(DriveSpec[0]), ':', '\\', 0};
> +        *pfExists = GetDriveTypeW(root) != DRIVE_NO_ROOT_DIR ? VARIANT_TRUE : VARIANT_FALSE;
> +    }

Not necessary wrong, but it'd be better if all that validation was 
GetDriveTypeW responsibility. I don't see many tests for it in 
kernel32/tests, could you please add some, so we can get rid of this 
extra logic? I haven't looked much at its implementation but it feels 
like DRIVE_UNKNOWN would also qualify as non-existent drive.