* string.c (rb_str_subseq): don't use rb_str_drop_bytes for short

  string.


git-svn-id: http://svn.ruby-lang.org/repos/ruby/trunk@19628 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 8 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index d129338a4..8f778f198 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Sep 29 23:32:25 2008  Tanaka Akira  <akr@fsij.org>
+
+	* string.c (rb_str_subseq): don't use rb_str_drop_bytes for short
+	  string.
+
 Mon Sep 29 22:54:29 2008  Tadayoshi Funaba  <tadf@dotrb.org>
 
 	* lib/mathn.rb: added String#to_[rc].  moved def_canon.
diff --git a/string.c b/string.c
index cf7f484c7..6a6859b1f 100644
--- a/string.c
+++ b/string.c
@@ -1285,8 +1285,9 @@ rb_str_subseq(VALUE str, long beg, long len)
 {
     VALUE str2;
 
-    if (RSTRING_LEN(str) == beg + len) {
-        str2 = rb_str_new_shared(str);
+    if (RSTRING_LEN(str) == beg + len &&
+        RSTRING_EMBED_LEN_MAX < len) {
+        str2 = rb_str_new_shared(rb_str_new_frozen(str));
         rb_str_drop_bytes(str2, beg);
     }
     else {