Patch tx and header fetch handlers, no serialize in failure condition.

Author: evoskuil

src/interface/blockchain.cpp

@@ -156,11 +156,17 @@ void blockchain::fetch_block_header_by_height(server_node& node,
 void blockchain::block_header_fetched(const code& ec, header_const_ptr header,
     const message& request, send_handler handler)
 {
+    if (ec)
+    {
+        handler(message(request, ec));
+        return;
+    }
+
     // [ code:4 ]
     // [ block... ]
     const auto result = build_chunk(
     {
-        message::to_bytes(ec),
+        message::to_bytes(error::success),
         header->to_data(canonical_version)
     });
 

src/utility/fetch_helpers.cpp

@@ -109,9 +109,15 @@ bool unwrap_fetch_transaction_args(hash_digest& hash, const message& request)
 void transaction_fetched(const code& ec, transaction_ptr tx, size_t, size_t,
     const message& request, send_handler handler)
 {
+    if (ec)
+    {
+        handler(message(request, ec));
+        return;
+    }
+
     const auto result = build_chunk(
     {
-        message::to_bytes(ec),
+        message::to_bytes(error::success),
         tx->to_data(version::level::canonical)
     });