* ext/psych/yaml/api.c (yaml_scalar_event_initialize): fix possible
  integer overflow.
  (yaml_document_add_scalar): ditto.
  (yaml_document_add_sequence): ditto.
   (yaml_document_add_mapping): ditto.

* ext/psych/yaml/loader.c (yaml_parser_load_scalar): ditto.
  (yaml_parser_load_sequence): ditto.
  (yaml_parser_load_mapping): ditto.

* ext/psych/yaml/scanner.c (yaml_parser_roll_indent): suppress
  warnigs.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44816 b2dd03c8-39d4-4d8f-98ff-823fe69b080e