Fix segmentation fault that can occur when reading from a response bucket wrapping a socket bucket (indirectly through a barrier). When all data is read from a socket bucket, an extra read might be needed to get EOF returned. Test for this situation to avoid working on a buffer of length 0.
Fix segmentation fault that can occur when reading from a response bucket
wrapping a socket bucket (indirectly through a barrier).
When all data is read from a socket bucket, an extra read might be needed
to get EOF returned. Test for this situation to avoid working on a buffer
of length 0.

Found by: Arfrever Frehtes Taifersar Arahesis

* buckets/buckets.c
  (serf_linebuf_fetch): check for EOF and length 0 when reading from the 
   data stream, return (early) if found.

zhengcq315/serf,wzugang/serf,pengdu/serf,google-code-export/serf,blueszhangsh/serf,google-code-export/serf,TommyU/serf,alex1818/serf,zhengcq315/serf,KyleSanderson/serf,liuzongquan/serf,yesoce/serf,sworda/serf,SirJson/serf,justinweb/serf,lazysoez/serf,yesoce/serf,alex1818/serf,soufianeEL/serf,x-clone/serf,zhengcq315/serf,alex1818/serf,lazysoez/serf,sworda/serf,blueszhangsh/serf,justinweb/serf,TommyU/serf,krime/serf,lazysoez/serf,SirJson/serf,stoneCC/serf,krime/serf,idomon/serf,alex1818/serf,pengdu/serf,zhengcq315/serf,zhupan/serf,google-code-export/serf,TommyU/serf,muthusuba/serf,Manouchehri/serf,wzugang/serf,blueszhangsh/serf,lazysoez/serf,blueszhangsh/serf,stoneCC/serf,soufianeEL/serf,Manouchehri/serf,SirJson/serf,sworda/serf,Manouchehri/serf,liuzongquan/serf,idomon/serf,justinweb/serf,google-code-export/serf,x-clone/serf,wzugang/serf,pengdu/serf,muthusuba/serf,soufianeEL/serf,x-clone/serf,zhupan/serf,KyleSanderson/serf,wzugang/serf,liuzongquan/serf,pengdu/serf,muthusuba/serf,KyleSanderson/serf,KyleSanderson/serf,TommyU/serf,justinweb/serf,Manouchehri/serf,yesoce/serf,liuzongquan/serf,SirJson/serf,yesoce/serf,soufianeEL/serf,krime/serf,sworda/serf,muthusuba/serf,idomon/serf,zhupan/serf,krime/serf,idomon/serf,zhupan/serf,stoneCC/serf,stoneCC/serf,x-clone/serf