From 62219add6906cafdaf020f74b1385798df1837c5 Mon Sep 17 00:00:00 2001
From: Vinnie Falco <vinnie.falco@gmail.com>
Date: Mon, 20 Jun 2016 09:40:35 -0400
Subject: [PATCH] Initialize Writer in prepare:

Writer requires a call to Writer::init to call content_length. This
changes prepare to correctly call init. A consequences is that
prepare can now throw unexpectedly for user-defined writers that
can fail their initialization.
---
 include/beast/http/impl/message_v1.ipp | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/include/beast/http/impl/message_v1.ipp b/include/beast/http/impl/message_v1.ipp
index d0b69e4e..e2a2568d 100644
--- a/include/beast/http/impl/message_v1.ipp
+++ b/include/beast/http/impl/message_v1.ipp
@@ -8,6 +8,7 @@
 #ifndef BEAST_HTTP_IMPL_MESSAGE_V1_IPP
 #define BEAST_HTTP_IMPL_MESSAGE_V1_IPP
 
+#include <beast/core/error.hpp>
 #include <beast/http/rfc7230.hpp>
 #include <beast/http/detail/has_content_length.hpp>
 #include <boost/optional.hpp>
@@ -87,7 +88,11 @@ prepare_content_length(prepare_info& pi,
         std::true_type)
 {
     typename Body::writer w(msg);
-    //w.init(ec); // VFALCO This is a design problem!
+    // VFALCO This is a design problem!
+    error_code ec;
+    w.init(ec);
+    if(ec)
+        throw system_error{ec};
     pi.content_length = w.content_length();
 }