Move nesting limit to scanner only

The scanner now checks combined block+flow nesting
depth, making the parser-level checks redundant.
Remove them and unify the flow-level check to use
STACK_LIMIT for consistency with roll_indent.

Author: ingydotnet

src/parser.c

@@ -82,10 +82,6 @@ yaml_parser_set_parser_error_context(yaml_parser_t *parser,
         const char *context, yaml_mark_t context_mark,
         const char *problem, yaml_mark_t problem_mark);
 
-static int
-yaml_maximum_level_reached(yaml_parser_t *parser,
-        yaml_mark_t context_mark, yaml_mark_t problem_mark);
-
 /*
  * State functions.
  */
@@ -229,15 +225,6 @@ yaml_parser_set_parser_error_context(yaml_parser_t *parser,
     return 0;
 }
 
-static int
-yaml_maximum_level_reached(yaml_parser_t *parser,
-        yaml_mark_t context_mark, yaml_mark_t problem_mark)
-{
-    yaml_parser_set_parser_error_context(parser,
-            "while parsing", context_mark, "Maximum nesting level reached, set with yaml_set_max_nest_level())", problem_mark);
-    return 0;
-}
-
 /*
  * State dispatcher.
  */
@@ -677,43 +664,27 @@ yaml_parser_parse_node(yaml_parser_t *parser, yaml_event_t *event,
                 return 1;
             }
             else if (token->type == YAML_FLOW_SEQUENCE_START_TOKEN) {
-                if (!STACK_LIMIT(parser, parser->indents, MAX_NESTING_LEVEL - parser->flow_level)) {
-                    yaml_maximum_level_reached(parser, start_mark, token->start_mark);
-                    goto error;
-                }
                 end_mark = token->end_mark;
                 parser->state = YAML_PARSE_FLOW_SEQUENCE_FIRST_ENTRY_STATE;
                 SEQUENCE_START_EVENT_INIT(*event, anchor, tag, implicit,
                         YAML_FLOW_SEQUENCE_STYLE, start_mark, end_mark);
                 return 1;
             }
             else if (token->type == YAML_FLOW_MAPPING_START_TOKEN) {
-                if (!STACK_LIMIT(parser, parser->indents, MAX_NESTING_LEVEL - parser->flow_level)) {
-                    yaml_maximum_level_reached(parser, start_mark, token->start_mark);
-                    goto error;
-                }
                 end_mark = token->end_mark;
                 parser->state = YAML_PARSE_FLOW_MAPPING_FIRST_KEY_STATE;
                 MAPPING_START_EVENT_INIT(*event, anchor, tag, implicit,
                         YAML_FLOW_MAPPING_STYLE, start_mark, end_mark);
                 return 1;
             }
             else if (block && token->type == YAML_BLOCK_SEQUENCE_START_TOKEN) {
-                if (!STACK_LIMIT(parser, parser->indents, MAX_NESTING_LEVEL - parser->flow_level)) {
-                    yaml_maximum_level_reached(parser, start_mark, token->start_mark);
-                    goto error;
-                }
                 end_mark = token->end_mark;
                 parser->state = YAML_PARSE_BLOCK_SEQUENCE_FIRST_ENTRY_STATE;
                 SEQUENCE_START_EVENT_INIT(*event, anchor, tag, implicit,
                         YAML_BLOCK_SEQUENCE_STYLE, start_mark, end_mark);
                 return 1;
             }
             else if (block && token->type == YAML_BLOCK_MAPPING_START_TOKEN) {
-                if (!STACK_LIMIT(parser, parser->indents, MAX_NESTING_LEVEL - parser->flow_level)) {
-                    yaml_maximum_level_reached(parser, start_mark, token->start_mark);
-                    goto error;
-                }
                 end_mark = token->end_mark;
                 parser->state = YAML_PARSE_BLOCK_MAPPING_FIRST_KEY_STATE;
                 MAPPING_START_EVENT_INIT(*event, anchor, tag, implicit,

src/scanner.c

@@ -1181,7 +1181,7 @@ yaml_parser_increase_flow_level(yaml_parser_t *parser)
         return 0;
     }
 
-    if (parser->flow_level + (int)(parser->indents.top - parser->indents.start) >= MAX_NESTING_LEVEL) {
+    if (!STACK_LIMIT(parser, parser->indents, MAX_NESTING_LEVEL - parser->flow_level)) {
         return yaml_parser_set_scanner_error(parser,
                 "while increasing flow level", parser->mark,
                 "exceeded maximum nesting depth");