Addendum to cpp-netlib#35

This fix improves upon the earlier commit to make the implementation more predictable
and semantically consistent with the interface for both the put and post methods.

Author: deanberris

boost/network/protocol/http/client/facade.hpp

@@ -40,30 +40,44 @@ namespace boost { namespace network { namespace http {
         }
 
         response const post (request request_, string_type const & content_type, string_type const & body_) {
+            if (!boost::empty(headers(request_)["Content-Type"]))
+                request_ << remove_header("Content-Type");
+
             request_ << ::boost::network::body(body_)
+                << header("Content-Type", content_type)
                 << header("Content-Length", boost::lexical_cast<string_type>(body_.size()));
-            if (!boost::empty(headers(request_)["Content-Type"]))
-                request_ << header("Content-Type", content_type);
             return post(request_);
         }
 
         response const post (request const & request_, string_type const & body_) {
-            return post(request_, "x-application/octet-stream", body_);
+            string_type content_type = "x-application/octet-stream";
+            typename headers_range<request>::type content_type_headers =
+                headers(request_)["Content-Type"];
+            if (!boost::empty(content_type_headers))
+                content_type = boost::begin(content_type_headers)->second;
+            return post(request_, content_type, body_);
         }
 
         response const put (request const & request_) {
             return static_cast<Derived*>(this)->request_skeleton(request_, "PUT", true);
         }
 
         response const put (request const & request_, string_type const & body_) {
-            return put(request_, "x-application/octet-stream", body_);
+            string_type content_type = "x-application/octet-stream";
+            typename headers_range<request>::type content_type_headers =
+                headers(request_)["Content-Type"];
+            if (!boost::empty(content_type_headers))
+                content_type = boost::begin(content_type_headers)->second;
+            return put(request_, content_type, body_);
         }
 
         response const put (request request_, string_type const & content_type, string_type const & body_) {
+            if (!boost::empty(headers(request_)["Content-Type"]))
+                request_ << remove_header("Content-Type");
+
             request_ << ::boost::network::body(body_)
+                << header("Content-Type", content_type)
                 << header("Content-Length", boost::lexical_cast<string_type>(body_.size()));
-            if (!boost::empty(headers(request_)["Content-Type"]))
-                request_ << header("Content-Type", content_type);
             return put(request_);
         }