Make ripper support **nil syntax

The on_params hook will use :nil as the keyword rest argument.
There is a new on_nokw_param hook as well.

This fixes a type issue in the previous code, where an ID was
passed where a VALUE was the declared type.  The symbol :nil is
passed instead of the id.

2 files changed, 19 insertions, 3 deletions

diff --git a/parse.y b/parse.y
index c7c43e3278..c575dfdded 100644
--- a/parse.y
+++ b/parse.y
@@ -1034,6 +1034,7 @@ static void token_info_warn(struct parser_params *p, const char *token, token_in
 %type <id>   cname fname op f_rest_arg f_block_arg opt_f_block_arg f_norm_arg f_bad_arg
 %type <id>   f_kwrest f_label f_arg_asgn call_op call_op2 reswords relop dot_or_colon
 %type <id>   p_kwrest
+%type <id>   f_no_kwarg
 %token END_OF_INPUT 0	"end-of-input"
 %token <id> '.'
 /* escaped chars, should be ignored otherwise */
@@ -3247,7 +3248,7 @@ block_args_tail	: f_block_kwarg ',' f_kwrest opt_f_block_arg
 		    }
 		| f_no_kwarg opt_f_block_arg
 		    {
-			$$ = new_args_tail(p, Qnone, rb_intern("nil"), $2, &@1);
+			$$ = new_args_tail(p, Qnone, ID2SYM(rb_intern("nil")), $2, &@1);
 		    }
 		| f_block_arg
 		    {
@@ -4718,7 +4719,7 @@ args_tail	: f_kwarg ',' f_kwrest opt_f_block_arg
 		    }
 		| f_no_kwarg opt_f_block_arg
 		    {
-			$$ = new_args_tail(p, Qnone, rb_intern("nil"), $2, &@1);
+			$$ = new_args_tail(p, Qnone, ID2SYM(rb_intern("nil")), $2, &@1);
 		    }
 		| f_block_arg
 		    {
@@ -4977,6 +4978,11 @@ kwrest_mark	: tPOW
 		;
 
 f_no_kwarg	: kwrest_mark keyword_nil
+		    {
+		    /*%%%*/
+		    /*% %*/
+		    /*% ripper: nokw_param!(Qnil) %*/
+		    }
 		;
 
 f_kwrest	: kwrest_mark tIDENTIFIER
@@ -11136,7 +11142,7 @@ new_args_tail(struct parser_params *p, NODE *kw_args, ID kw_rest_arg, ID block,
 	args->kw_rest_arg = NEW_DVAR(kw_rest_arg, loc);
 	args->kw_rest_arg->nd_cflag = kw_bits;
     }
-    else if (kw_rest_arg == rb_intern("nil")) {
+    else if (kw_rest_arg == ID2SYM(rb_intern("nil"))) {
 	args->no_kwarg = 1;
     }
     else if (kw_rest_arg) {
diff --git a/test/ripper/test_parser_events.rb b/test/ripper/test_parser_events.rb
index 59d4ad3987..1bae1e31ad 100644
--- a/test/ripper/test_parser_events.rb
+++ b/test/ripper/test_parser_events.rb
@@ -944,6 +944,10 @@ class TestRipper::ParserEvents < Test::Unit::TestCase
     parse('a {|**x|}', :on_params) {|_, *v| thru_params = true; arg = v}
     assert_equal true, thru_params
     assert_equal [nil, nil, nil, nil, nil, "**x", nil], arg
+    thru_params = false
+    parse('a {|**nil|}', :on_params) {|_, *v| thru_params = true; arg = v}
+    assert_equal true, thru_params
+    assert_equal [nil, nil, nil, nil, nil, :nil, nil], arg
   end
 
   def test_params_mlhs
@@ -1153,6 +1157,12 @@ class TestRipper::ParserEvents < Test::Unit::TestCase
     assert_equal "x", thru_kwrest
   end
 
+  def test_nokw_param
+    thru_nokw = false
+    parse('def a(**nil) end', :on_nokw_param) {|n, val| thru_nokw = val}
+    assert_equal nil, thru_nokw
+  end
+
   def test_retry
     thru_retry = false
     parse('retry', :on_retry) {thru_retry = true}