Add keyrest to ruby2_keywords parameters [Bug #18011]

iseq.c

@@ -3116,9 +3116,18 @@ rb_iseq_parameters(const rb_iseq_t *iseq, int is_proc)
 	    rb_ary_push(args, a);
 	}
     }
-    if (body->param.flags.has_kwrest) {
+    if (body->param.flags.has_kwrest || body->param.flags.ruby2_keywords) {
+        ID param;
 	CONST_ID(keyrest, "keyrest");
-	rb_ary_push(args, PARAM(keyword->rest_start, keyrest));
+        PARAM_TYPE(keyrest);
+        if (body->param.flags.has_kwrest &&
+            rb_id2str(param = PARAM_ID(keyword->rest_start))) {
+            rb_ary_push(a, ID2SYM(param));
+        }
+        else if (body->param.flags.ruby2_keywords) {
+            rb_ary_push(a, ID2SYM(idPow));
+        }
+	rb_ary_push(args, a);
     }
     if (body->param.flags.has_block) {
 	CONST_ID(block, "block");

proc.c

@@ -3097,7 +3097,12 @@ method_inspect(VALUE method)
                 }
             }
             else if (kind == keyrest) {
-                rb_str_catf(str, "**%"PRIsVALUE, name);
+                if (name != ID2SYM(idPow)) {
+                    rb_str_catf(str, "**%"PRIsVALUE, name);
+                }
+                else if (i > 0) {
+                    rb_str_set_len(str, RSTRING_LEN(str) - 2);
+                }
             }
             else if (kind == block) {
                 if (name == ID2SYM('&')) {

test/ruby/test_method.rb

@@ -578,7 +578,7 @@ class TestMethod < Test::Unit::TestCase
     assert_equal([[:req, :a], [:opt, :b], [:rest, :c], [:req, :d], [:keyreq, :e], [:key, :f], [:keyrest, :o]], method(:mk8).parameters)
     assert_equal([[:nokey]], method(:mnk).parameters)
     # pending
-    assert_equal([[:rest, :*], [:block, :&]], method(:mf).parameters)
+    assert_equal([[:rest, :*], [:keyrest, :**], [:block, :&]], method(:mf).parameters)
   end
 
   def test_unbound_parameters
@@ -604,7 +604,7 @@ class TestMethod < Test::Unit::TestCase
     assert_equal([[:req, :a], [:opt, :b], [:rest, :c], [:req, :d], [:keyreq, :e], [:key, :f], [:keyrest, :o]], self.class.instance_method(:mk8).parameters)
     assert_equal([[:nokey]], self.class.instance_method(:mnk).parameters)
     # pending
-    assert_equal([[:rest, :*], [:block, :&]], self.class.instance_method(:mf).parameters)
+    assert_equal([[:rest, :*], [:keyrest, :**], [:block, :&]], self.class.instance_method(:mf).parameters)
   end
 
   def test_bmethod_bound_parameters

test/ruby/test_syntax.rb

@@ -1638,7 +1638,8 @@ eom
       assert_equal(-1, obj.method(:foo).arity)
       parameters = obj.method(:foo).parameters
       assert_equal(:rest, parameters.dig(0, 0))
-      assert_equal(:block, parameters.dig(1, 0))
+      assert_equal(:keyrest, parameters.dig(1, 0))
+      assert_equal(:block, parameters.dig(2, 0))
     end
   end