string.c: fix ASCII-only on succ

* string.c (str_succ): clear coderange cache when no alpha-numeric
  character case, carried part may become ASCII-only.
  [ruby-core:83062] [Bug #13952]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60066 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 1 insertions, 0 deletions

diff --git a/string.c b/string.c
index e1bd9a052e..0c782a430f 100644
--- a/string.c
+++ b/string.c
@@ -4079,6 +4079,7 @@ str_succ(VALUE str)
             }
             carry_pos = s - sbeg;
 	}
+	ENC_CODERANGE_SET(str, ENC_CODERANGE_UNKNOWN);
     }
     RESIZE_CAPA(str, slen + carry_len);
     sbeg = RSTRING_PTR(str);