[PATCH 1/5] hid: Correctly sign-extend all values in HidP_GetScaledUsageValue().

[Aric Stewart]

Signed-off-by: Aric Stewart <aric at codeweavers.com>

On 2/12/19 12:06 AM, Zebediah Figura wrote:
> Signed-off-by: Zebediah Figura <z.figura12 at gmail.com>
> ---
>   dlls/hid/hidp.c | 15 ++++++++++++++-
>   1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/dlls/hid/hidp.c b/dlls/hid/hidp.c
> index 15d827edf1..ac5f22203d 100644
> --- a/dlls/hid/hidp.c
> +++ b/dlls/hid/hidp.c
> @@ -259,6 +259,19 @@ static NTSTATUS find_value(HIDP_REPORT_TYPE ReportType, USAGE UsagePage, USHORT
>       return HIDP_STATUS_USAGE_NOT_FOUND;
>   }
>   
> +static LONG sign_extend(ULONG value, const WINE_HID_ELEMENT *element)
> +{
> +    UINT bit_count = element->bitCount;
> +
> +    if ((value & (1 << (bit_count - 1)))
> +            && element->ElementType == ValueElement
> +            && element->caps.value.LogicalMin < 0)
> +    {
> +        value -= (1 << bit_count);
> +    }
> +    return value;
> +}
> +
>   NTSTATUS WINAPI HidP_GetScaledUsageValue(HIDP_REPORT_TYPE ReportType, USAGE UsagePage,
>                                            USHORT LinkCollection, USAGE Usage, PLONG UsageValue,
>                                            PHIDP_PREPARSED_DATA PreparsedData, PCHAR Report, ULONG ReportLength)
> @@ -277,7 +290,7 @@ NTSTATUS WINAPI HidP_GetScaledUsageValue(HIDP_REPORT_TYPE ReportType, USAGE Usag
>                                element->valueStartBit, element->bitCount, &rawValue);
>           if (rc != HIDP_STATUS_SUCCESS)
>               return rc;
> -        *UsageValue = rawValue;
> +        *UsageValue = sign_extend(rawValue, element);
>       }
>   
>       return rc;
>