[PATCH] Fix wrong button label and mask copy on OS X

[Jeremy Huddleston]

Reviewed-by: Jeremy Huddleston <jeremyhu at apple.com>
Tested-by: Jeremy Huddleston <jeremyhu at apple.com>

On Mar 14, 2012, at 7:06 PM, Peter Hutterer <peter.hutterer at who-t.net> wrote:

> Regression introduced in c1a5a70b51f12dedf354102217c7cd4247ed3a4b.
> 
> If double-padding is applied, the length of the mask on the wire may be
> smaller than libXi's mask_len. When copying, only the wire length must be
> copied, with the remainder set to 0.
> When advancing to the button labels, the wire length matters, not libXi's
> internal length.
> 
> Reported-by: Jeremy Huddleston <jeremyhu at apple.com>
> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
> ---
> I think this one should fix the issue. You're seeing this because
> the ifs in pad_to_double get triggered on your box, but not on mine. That's
> a separate issue I guess, shouldn't trigger on OS X. nonetheless, this bug
> would be present on MIPS N32 too.
> 
> src/XExtInt.c |   11 +++++++++--
> 1 files changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/src/XExtInt.c b/src/XExtInt.c
> index 89c0894..0c64f9a 100644
> --- a/src/XExtInt.c
> +++ b/src/XExtInt.c
> @@ -1610,12 +1610,14 @@ copy_classes(XIDeviceInfo* to, xXIAnyInfo* from, int *nclasses)
>                     int struct_size;
>                     int state_size;
>                     int labels_size;
> +                    int wire_mask_size;
> 
>                     cls_wire = (xXIButtonInfo*)any_wire;
>                     sizeXIButtonClassType(cls_wire->num_buttons,
>                                           &struct_size, &state_size,
>                                           &labels_size);
>                     cls_lib = next_block(&ptr_lib, struct_size);
> +                    wire_mask_size = ((cls_wire->num_buttons + 7)/8 + 3)/4 * 4;
> 
>                     cls_lib->type = cls_wire->type;
>                     cls_lib->sourceid = cls_wire->sourceid;
> @@ -1623,10 +1625,14 @@ copy_classes(XIDeviceInfo* to, xXIAnyInfo* from, int *nclasses)
>                     cls_lib->state.mask_len = state_size;
>                     cls_lib->state.mask = next_block(&ptr_lib, state_size);
>                     memcpy(cls_lib->state.mask, &cls_wire[1],
> -                           cls_lib->state.mask_len);
> +                           wire_mask_size);
> +                    if (state_size != wire_mask_size)
> +                        memset(&cls_lib->state.mask[wire_mask_size], 0,
> +                               state_size - wire_mask_size);
> 
>                     cls_lib->labels = next_block(&ptr_lib, labels_size);
> -                    atoms =(uint32_t*)((char*)&cls_wire[1] + cls_lib->state.mask_len);
> +
> +                    atoms =(uint32_t*)((char*)&cls_wire[1] + wire_mask_size);
>                     for (j = 0; j < cls_lib->num_buttons; j++)
>                         cls_lib->labels[j] = *atoms++;
> 
> -- 
> 1.7.7.6
> 
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