addition to fixes about #4700, 4701

libmysqld/lib_sql.cc:
  Comment added
sql/sql_prepare.cc:
  Necessary line added to emb_insert_params_with_log

libmysqld/lib_sql.cc

@@ -108,6 +108,12 @@ emb_advanced_command(MYSQL *mysql, enum enum_server_command command,
   if (!skip_check)
     result= thd->net.last_errno ? -1 : 0;
 
+  /*
+    If mysql->field_count is set it means the parsing of the query was OK
+    and metadata was returned (see Protocol::send_fields).
+    In this case we postpone the error to be returned in mysql_stmt_store_result
+    (see emb_read_rows) to behave just as standalone server.
+  */
   if (!mysql->field_count)
     embedded_get_error(mysql);
   mysql->server_status= thd->server_status;

sql/sql_prepare.cc

@@ -737,6 +737,7 @@ static bool emb_insert_params_withlog(Prepared_statement *stmt, String *query)
       else
       {
         uchar *buff= (uchar*)client_param->buffer;
+	param->unsigned_flag= client_param->is_unsigned;
         param->set_param_func(param, &buff,
                               client_param->length ? 
                               *client_param->length :