From 5004e33f8de3b7ce8208421da512102c95c597cb Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Fri, 31 Jul 2009 01:54:14 +0000
Subject: [PATCH] * parse.y (literal_concat_gen): reduced unnecessary node at
 string   literal concatenation with empty head dstr.  [ruby-dev:38968]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@24333 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog | 5 +++++
 parse.y   | 8 +++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 4d052c9f65..59459ffa19 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Jul 31 10:54:08 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* parse.y (literal_concat_gen): reduced unnecessary node at string
+	  literal concatenation with empty head dstr.  [ruby-dev:38968]
+
 Fri Jul 31 02:57:39 2009  Yusuke Endoh  <mame@tsg.ne.jp>
 
 	* parse.y (literal_concat_gen): NODE_DSTR was incorrectly handled as
diff --git a/parse.y b/parse.y
index e6c921e57a..80fef61f34 100644
--- a/parse.y
+++ b/parse.y
@@ -7832,8 +7832,14 @@ literal_concat_gen(struct parser_params *parser, NODE *head, NODE *tail)
 	    rb_gc_force_recycle((VALUE)head);
 	    head = tail;
 	}
+	else if (NIL_P(tail->nd_lit)) {
+	    list_concat(head, tail->nd_next);
+	    rb_gc_force_recycle((VALUE)tail);
+	}
 	else {
-	    list_concat(head, NEW_ARRAY(tail));
+	    nd_set_type(tail, NODE_ARRAY);
+	    tail->nd_head = NEW_STR(tail->nd_lit);
+	    list_concat(head, tail);
 	}
 	break;