parse.y: precedence of duplicated keys

* parse.y (assocs): concatenate splatted literal hashes.  the
  former key has precedence even if duplicated literal keys
  follow.  [ruby-core:65368] [Bug #10315]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47877 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Sat Oct 11 13:46:53 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* parse.y (assocs): concatenate splatted literal hashes.  the
+	  former key has precedence even if duplicated literal keys
+	  follow.  [ruby-core:65368] [Bug #10315]
+
 Sat Oct 11 12:27:03 2014  Yuki Yugui Sonoda  <yugui@yugui.jp>
 
 	* configure.in (RUBY_NACL): automatically locate pnacl-clang.

parse.y

@@ -4931,7 +4931,15 @@ assocs		: assoc
 		| assocs ',' assoc
 		    {
 		    /*%%%*/
-			$$ = list_concat($1, $3);
+			NODE *assocs = $1;
+			NODE *tail = $3;
+			if (assocs->nd_head &&
+			    !tail->nd_head && nd_type(tail->nd_next) == NODE_ARRAY &&
+			    nd_type(tail->nd_next->nd_head) == NODE_HASH) {
+			    /* DSTAR */
+			    tail = tail->nd_next->nd_head->nd_head;
+			}
+			$$ = list_concat(assocs, tail);
 		    /*%
 			$$ = rb_ary_push($1, $3);
 		    %*/

test/ruby/test_syntax.rb

@@ -112,6 +112,10 @@ class TestSyntax < Test::Unit::TestCase
     assert_equal([11, 22], o.kw(k2: 22, **h))
     assert_equal([11, 12], o.kw(**h, **{k2: 22}))
     assert_equal([11, 22], o.kw(**{k2: 22}, **h))
+
+    bug10315 = '[ruby-core:65368] [Bug #10315]'
+    assert_equal([22, 2], o.kw(**{k1: 22}, **{k1: 23}), bug10315)
+
     h = {k3: 31}
     assert_raise(ArgumentError) {o.kw(**h)}
     h = {"k1"=>11, k2: 12}