When using cpp-netlib-0.11.2-final and async client with body callback function:

boost::network::http::client::options options;
options.timeout( timeout_seconds );
options.follow_redirects( true );

boost::network::http::client client( options );
client.get( request, callback );

The callback is not called when some network etc. errors occur. I observed it that when timeout should occur my callback function is still not called, but when I looked at cpp-netlib's async_normal.hpp file I found not only for timeout, but in many places in which body_promise IS set (either to empty value or exception), but callback either IS NOT called at all, or is called with uninitialized boost::system::error_code instead of the same error code body_promise was set, which would make my own callback function expect another call instead of finish the processing (since uninitialized error_code means no error occurred and we are still waiting for boost::asio::error::eof or other error to finish the processing).

The issue is also present on the current master branch. I created a pull request with proposed fix for this.