[PATCH xserver] fix check pointer dereferences before using them

[Tiago Vignatti]

Hi,

Playing a bit more with coverity tool I found these pointer dereferences 
before them be actually checked. Probably mostly are harmless, but it's bad 
habit of codification.

I just compiled and ran here, without checking properly if they are all 
working fine. Please, take a look on it.

Thanks,


Tiago Vignatti (9):
  xfree86: check for NULL pointer before dereferences it in parser code
  exa: check for NULL pointer before dereferences it
  Xi: check for NULL pointer before dereferences it in ListButtonInfo
  Xi: check for NULL pointer before dereferences it in DeviceFocusEvent
  dix: check for NULL pointer before dereferences it in
    DeviceEnterLeaveEvent
  exa: don't need to check for NULL pointer if we already assumed it
    has a value
  xkb: check for NULL pointer before dereferences it in
    XkbWriteXKBSymbols
  mi: check for NULL pointer before dereferences it in
    miPointerSetPosition
  xkb: check for NULL pointer before dereferences it in
    XkbAddClientResource

 Xi/exevents.c            |    4 +++-
 Xi/xiquerydevice.c       |    5 ++++-
 dix/events.c             |    8 ++++++--
 exa/exa.c                |    2 --
 exa/exa_classic.c        |    3 ++-
 exa/exa_driver.c         |    4 +++-
 exa/exa_mixed.c          |    3 ++-
 hw/xfree86/parser/scan.c |    9 +++++++--
 mi/mipointer.c           |    6 +++---
 xkb/xkbEvents.c          |    2 +-
 xkb/xkbout.c             |    5 ++++-
 11 files changed, 35 insertions(+), 16 deletions(-)