From 16759238ad5a19e784f73a66ba5cacf7ee274262 Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Sat, 30 Sep 2017 00:01:23 +0000
Subject: [PATCH] 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
---
 string.c                 | 1 +
 test/ruby/test_string.rb | 5 +++++
 2 files changed, 6 insertions(+)

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);
diff --git a/test/ruby/test_string.rb b/test/ruby/test_string.rb
index ec90193546..75da42eeef 100644
--- a/test/ruby/test_string.rb
+++ b/test/ruby/test_string.rb
@@ -1872,6 +1872,11 @@ CODE
 
     assert_equal("!", " ".succ)
     assert_equal("", "".succ)
+
+    bug = '[ruby-core:83062] [Bug #13952]'
+    s = "\xff".b
+    assert_not_predicate(s, :ascii_only?)
+    assert_predicate(s.succ, :ascii_only?, bug)
   end
 
   def test_succ!