Robson Braga Araujo reported bug #1618359

(http://curl.haxx.se/bug/view.cgi?id=1618359) and subsequently provided a
patch for it: when downloading 2 zero byte files in a row, curl 7.16.0
enters an infinite loop, while curl 7.16.1-20061218 does one additional
unnecessary request.

Fix: During the "Major overhaul introducing http pipelining support and
shared connection cache within the multi handle." change, headerbytecount
was moved to live in the Curl_transfer_keeper structure. But that structure
is reset in the Transfer method, losing the information that we had about
the header size. This patch moves it back to the connectdata struct.

RELEASE-NOTES

@@ -36,6 +36,7 @@ This release includes the following bugfixes:
  o getting FTP response code errors when using the multi-interface caused
    libcurl to leak memory
  o no more SIGPIPE when GnuTLS is used
+ o FTP downloading 2 zero byte files in a row
 
 Other curl-related news:
 
@@ -54,6 +55,7 @@ advice from friends like these:
  James Housley, Olaf Stueben, Yang Tse, Gisle Vanem, Bradford Bruce,
  Ciprian Badescu, Dmitriy Sergeyev, Nir Soffer, Venkat Akella, Toon Verwaest,
  Matt Witherspoon, Alexey Simak, Martin Skinner, Sh Diao, Jared Lundell,
- Stefan Krause, Sebastien Willemijns, Alexey Simak, Brendan Jurd
+ Stefan Krause, Sebastien Willemijns, Alexey Simak, Brendan Jurd,
+ Robson Braga Araujo
 
         Thanks! (and sorry if I forgot to mention someone)