fix a sign problem with valuator data.
Without this patch, any negative valuator value is wrong when returned from XQueryDeviceState(). This is a regression from at least xserver 1.4. Valuator data is set in dix/getevents.c:set_valuators() by copying signed int values into an unsigned int field DeviceEvent.valuators.data. That data is converted into a double with an implicit cast by assignment to axisVal[i] in Xi/exevents.c:UpdateDeviceState(). That double is converted back to a signed int in queryst.c:ProcXQueryDeviceState(). If the original value in set_valuators() is negative, the double value will be > 2^31 and the conversion back to a signed int is undefined. (Although I consistently see the value -2^31.) Fix this by changing the definition of DeviceEvent.valuators.data from uint32_t to int32_t. Signed-off-by: Joe Shaw <joeshaw@litl.com> Reviewed-by: Chase Douglas <chase.douglas@canonical.com> Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net> Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
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@ -210,7 +210,7 @@ set_valuators(DeviceIntPtr dev, DeviceEvent* event, int first_valuator,
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}
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memcpy(&event->valuators.data[first_valuator],
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valuators, num_valuators * sizeof(uint32_t));
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valuators, num_valuators * sizeof(int32_t));
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}
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@ -99,7 +99,7 @@ struct _DeviceEvent
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struct {
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uint8_t mask[(MAX_VALUATORS + 7)/8]; /**< Valuator mask */
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uint8_t mode[(MAX_VALUATORS + 7)/8]; /**< Valuator mode (Abs or Rel)*/
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uint32_t data[MAX_VALUATORS]; /**< Valuator data */
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int32_t data[MAX_VALUATORS]; /**< Valuator data */
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int32_t data_frac[MAX_VALUATORS]; /**< Fractional part for data */
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} valuators;
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struct {
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