merges r24332 and r24333 from trunk into ruby_1_9_1.

--
* parse.y (literal_concat_gen): NODE_DSTR was incorrectly handled as
  NODE_STR.  [ruby-dev:38968]

* bootstraptest/test_syntax.rb: add a test for above.
--
* parse.y (literal_concat_gen): reduced unnecessary node at string
  literal concatenation with empty head dstr.  [ruby-dev:38968]

git-svn-id: http://svn.ruby-lang.org/repos/ruby/branches/ruby_1_9_1@24453 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 4 insertions, 0 deletions

diff --git a/parse.y b/parse.y
index 84314c816..3961733cd 100644
--- a/parse.y
+++ b/parse.y
@@ -7880,6 +7880,10 @@ 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 {
 	    nd_set_type(tail, NODE_ARRAY);
 	    tail->nd_head = NEW_STR(tail->nd_lit);