Running Xephyr under valgrind reveals that we're sending some
uninitialized memory over the wire (particularly, the leftover padding
that comes from rounding extraLen to the next 32-bit multiple).
Solve by calloc()ing the memory instead of malloc()ing (the alternative
would be to memset just the padding, but I'm not sure it's more
convenient.)
Signed-off-by: Giuseppe Bilotta <giuseppe.bilotta@gmail.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
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