compile.c: non-destructive keyword splat

* compile.c (compile_array_): make copy a first hash not to modify
  the argument itself.  keyword splat should be non-destructive.
  [ruby-core:62161] [Bug #9776]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45724 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Sat Apr 26 10:55:33 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* compile.c (compile_array_): make copy a first hash not to modify
+	  the argument itself.  keyword splat should be non-destructive.
+	  [ruby-core:62161] [Bug #9776]
+
 Sat Apr 26 08:05:36 2014  Tanaka Akira  <akr@fsij.org>
 
 	* test/ruby/test_process.rb (test_rlimit_nofile): Don't limit

compile.c

@@ -2479,6 +2479,7 @@ compile_array_(rb_iseq_t *iseq, LINK_ANCHOR *ret, NODE* node_root,
 			    if (i > 0 || !first) ADD_INSN(ret, line, swap);
 			    COMPILE(ret, "keyword splat", kw);
 			    ADD_SEND(ret, line, ID2SYM(id_core_hash_merge_kwd), nhash);
+			    if (nhash == INT2FIX(1)) ADD_SEND(ret, line, ID2SYM(rb_intern("dup")), INT2FIX(0));
 			}
 			first = 0;
 			break;

test/ruby/test_keyword.rb

@@ -439,6 +439,19 @@ class TestKeywordArguments < Test::Unit::TestCase
     assert_equal([1, 2, 1, [], {:f=>5}, 2, {}], a.new.foo(1, 2, f:5), bug8993)
   end
 
+  def test_splat_keyword_nondestructive
+    bug9776 = '[ruby-core:62161] [Bug #9776]'
+
+    h = {a: 1}
+    assert_equal({a:1, b:2}, {**h, b:2})
+    assert_equal({a:1}, h, bug9776)
+
+    pr = proc {|**opt| next opt}
+    assert_equal({a: 1}, pr.call(**h))
+    assert_equal({a: 1, b: 2}, pr.call(**h, b: 2))
+    assert_equal({a: 1}, h, bug9776)
+  end
+
   def test_gced_object_in_stack
     bug8964 = '[ruby-dev:47729] [Bug #8964]'
     assert_normal_exit %q{