[v2 2/2] winejoystick.drv: Disable joysticks via wine registry on Mac
Ken Thomases
ken at codeweavers.com
Mon Aug 29 15:02:29 CDT 2016
Hi,
On Aug 29, 2016, at 6:03 AM, David Lawrie <david.dljunk at gmail.com> wrote:
>
> +static void char_device_name_length(IOHIDDeviceRef device, char *name, int max_length)
> +{
> + CFStringRef str = copy_device_name(device);
> + CFIndex len = CFStringGetLength(str);
> +
> + if (name)
> + name[0] = 0;
> +
> + if (max_length >= len)
> + {
> + CFStringGetCString(str,name,max_length,kCFStringEncodingASCII);
> + CFRelease(str);
> + }
> + else
> + {
> + CFStringRef substr = CFStringCreateWithSubstring(kCFAllocatorDefault, str, CFRangeMake(0, max_length));
> + CFRelease(str);
> + CFStringGetCString(substr,name,max_length,kCFStringEncodingASCII);
> + CFRelease(substr);
> + }
> +}
I realize you based this function on code from DInput. Unfortunately, that code is pretty badly broken. CFStringGetLength() returns the length of the string in UTF-16 code units, which is basically the same as WCHARs. It's not meaningful to compare that to a buffer size that's in ASCII chars.
Using ASCII is wrong, too. If the name has any non-ASCII characters in it, the conversion will just fail. Second, it's potentially unnecessarily restrictive. Your device_disabled_registry() function, by virtue of using the "A" variant RegQueryValueEx(), uses the ANSI code page, not ASCII. The ANSI code page could maybe handle more names than ASCII would.
You could get a wide string and then use WideCharToMultiByte() to convert it to CP_ACP, but since you control all of the relevant code, it's just better to work with wide strings throughout. Change your device_disabled_registry() and get_config_key() functions to accept a wide string. Then, you can safely use CFStringGetLength() and CFStringGetCharacters() to acquire the WCHAR-based wide string from the CFString. You can just cast a WCHAR* to a UniChar*.
-Ken
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