From cc68af3d026a3ece1dd890fd3510ed9c26660bc6 Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Mon, 17 Apr 2017 13:38:34 +0000
Subject: [PATCH] string.c: improve insertion performace

* string.c (rb_str_splice_0): improve performace of single byte
  optimizable cases, insertion 7bit string to 7bit string.
  [ruby-dev:49984] [Bug #13228]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58383 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 string.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/string.c b/string.c
index b461f86a1f..cfeecd5a26 100644
--- a/string.c
+++ b/string.c
@@ -4397,6 +4397,7 @@ rb_str_splice_0(VALUE str, long beg, long len, VALUE val)
 {
     char *sptr;
     long slen, vlen = RSTRING_LEN(val);
+    int cr;
 
     if (beg == 0 && vlen == 0) {
 	rb_str_drop_bytes(str, len);
@@ -4404,7 +4405,7 @@ rb_str_splice_0(VALUE str, long beg, long len, VALUE val)
 	return;
     }
 
-    rb_str_modify(str);
+    str_modify_keep_cr(str);
     RSTRING_GETMEM(str, sptr, slen);
     if (len < vlen) {
 	/* expand string */
@@ -4412,6 +4413,11 @@ rb_str_splice_0(VALUE str, long beg, long len, VALUE val)
 	sptr = RSTRING_PTR(str);
     }
 
+    if (ENC_CODERANGE(str) == ENC_CODERANGE_7BIT)
+	cr = rb_enc_str_coderange(val);
+    else
+	cr = ENC_CODERANGE_UNKNOWN;
+
     if (vlen != len) {
 	memmove(sptr + beg + vlen,
 		sptr + beg + len,
@@ -4427,6 +4433,7 @@ rb_str_splice_0(VALUE str, long beg, long len, VALUE val)
     STR_SET_LEN(str, slen);
     TERM_FILL(&sptr[slen], TERM_LEN(str));
     OBJ_INFECT(str, val);
+    ENC_CODERANGE_SET(str, cr);
 }
 
 void