string.c: ASCII-incompatible is not ASCII only

* string.c (tr_trans): ASCII-incompatible encoding strings cannot
  be ASCII-only even if valid.  [ruby-core:83056] [Bug #13950]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60060 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 7 insertions, 2 deletions

diff --git a/string.c b/string.c
index 7e7ae7f0a8..e1bd9a052e 100644
--- a/string.c
+++ b/string.c
@@ -6637,7 +6637,7 @@ tr_trans(VALUE str, VALUE src, VALUE repl, int sflag)
 	}
     }
 
-    if (cr == ENC_CODERANGE_VALID)
+    if (cr == ENC_CODERANGE_VALID && rb_enc_asciicompat(e1))
 	cr = ENC_CODERANGE_7BIT;
     str_modify_keep_cr(str);
     s = RSTRING_PTR(str); send = RSTRING_END(str);
diff --git a/test/ruby/test_string.rb b/test/ruby/test_string.rb
index b1f3c3cfcb..ec90193546 100644
--- a/test/ruby/test_string.rb
+++ b/test/ruby/test_string.rb
@@ -2063,8 +2063,13 @@ CODE
     assert_equal(false, "\u3041\u3042".tr("\u3041", "a").ascii_only?)
 
     bug6156 = '[ruby-core:43335]'
+    bug13950 = '[ruby-core:83056] [Bug #13950]'
     str, range, star = %w[b a-z *].map{|s|s.encode("utf-16le")}
-    assert_equal(star, str.tr(range, star), bug6156)
+    result = str.tr(range, star)
+    assert_equal(star, result, bug6156)
+    assert_not_predicate(str, :ascii_only?)
+    assert_not_predicate(star, :ascii_only?)
+    assert_not_predicate(result, :ascii_only?, bug13950)
   end
 
   def test_tr!