Correctness fix in serf_linebuf_fetch().
Correctness fix in serf_linebuf_fetch().

* buckets/buckets.c
  (serf_linebuf_fetch): Do not call memcpy() with zero length and 
   possibly invalid pointer. The C99 standard (7.21.1/2) requires valid 
   data pointer even for zero length array for all functions unless 
   explicitly stated otherwise.

KyleSanderson/serf,lazysoez/serf,lazysoez/serf,stoneCC/serf,x-clone/serf,zhupan/serf,stoneCC/serf,pengdu/serf,alex1818/serf,google-code-export/serf,yesoce/serf,KyleSanderson/serf,yesoce/serf,zhengcq315/serf,SirJson/serf,alex1818/serf,x-clone/serf,google-code-export/serf,zhupan/serf,soufianeEL/serf,soufianeEL/serf,SirJson/serf,lazysoez/serf,soufianeEL/serf,google-code-export/serf,stoneCC/serf,zhengcq315/serf,yesoce/serf,alex1818/serf,zhengcq315/serf,pengdu/serf,soufianeEL/serf,pengdu/serf,pengdu/serf,alex1818/serf,yesoce/serf,zhupan/serf,stoneCC/serf,zhengcq315/serf,SirJson/serf,zhupan/serf,KyleSanderson/serf,x-clone/serf,KyleSanderson/serf,google-code-export/serf,lazysoez/serf,x-clone/serf,SirJson/serf