Hi,

        For normal header+body response, libcurl seems have no problem. However, for
header only response, like 304 (Not modified). After getting the header,
libcurl seems still get into select() in Transfer() and wait for 1 sec before
it return. It makes a serious performance impact for validating cached
object.
        
        The patch attach seems solved this problem, but haven't test it very much.

Jacky