merge revision(s) 67167: [Backport #15635]

	string.c: respect the actual encoding

	* string.c (rb_enc_str_coderange): respect the actual encoding of
	  if a BOM presents, and scan for the actual code range.
	  [ruby-core:91662] [Bug #15635]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_6@67181 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 3 insertions, 2 deletions

diff --git a/string.c b/string.c
index dcb28532cd..855d594b84 100644
--- a/string.c
+++ b/string.c
@@ -657,12 +657,13 @@ rb_enc_str_coderange(VALUE str)
     if (cr == ENC_CODERANGE_UNKNOWN) {
 	int encidx = ENCODING_GET(str);
 	rb_encoding *enc = rb_enc_from_index(encidx);
-	if (rb_enc_mbminlen(enc) > 1 && rb_enc_dummy_p(enc)) {
+	if (rb_enc_mbminlen(enc) > 1 && rb_enc_dummy_p(enc) &&
+            rb_enc_mbminlen(enc = get_actual_encoding(encidx, str)) == 1) {
 	    cr = ENC_CODERANGE_BROKEN;
 	}
 	else {
 	    cr = coderange_scan(RSTRING_PTR(str), RSTRING_LEN(str),
-				get_actual_encoding(encidx, str));
+                                enc);
 	}
         ENC_CODERANGE_SET(str, cr);
     }