add on_reason to get the reason string from a response parse

http_parser.c

@@ -402,6 +402,7 @@ size_t http_parser_execute (http_parser *parser,
   const char *header_field_mark = 0;
   const char *header_value_mark = 0;
   const char *url_mark = 0;
+  const char *reason_mark = 0;
 
   if (state == s_header_field)
     header_field_mark = data;
@@ -629,16 +630,16 @@ size_t http_parser_execute (http_parser *parser,
       }
 
       case s_res_status:
-        /* the human readable status. e.g. "NOT FOUND"
-         * we are not humans so just ignore this */
-        if (ch == CR) {
-          state = s_res_line_almost_done;
-          break;
-        }
-
-        if (ch == LF) {
-          state = s_header_field_start;
-          break;
+        switch (ch) {
+          case CR:
+            state = s_res_line_almost_done;
+            break;
+          case LF:
+            state = s_header_field_start;
+            break;
+          default:
+            CALLBACK(reason);
+            break;
         }
         break;
 

http_parser.h

@@ -146,6 +146,7 @@ enum flags
   XX(CB_path, "the on_path callback failed")                         \
   XX(CB_query_string, "the on_query_string callback failed")         \
   XX(CB_url, "the on_url callback failed")                           \
+  XX(CB_reason, "the on_reason callback failed")                     \
   XX(CB_fragment, "the on_fragment callback failed")                 \
   XX(CB_header_field, "the on_header_field callback failed")         \
   XX(CB_header_value, "the on_header_value callback failed")         \
@@ -236,6 +237,7 @@ struct http_parser {
 struct http_parser_settings {
   http_cb      on_message_begin;
   http_data_cb on_url;
+  http_data_cb on_reason;
   http_data_cb on_header_field;
   http_data_cb on_header_value;
   http_cb      on_headers_complete;