Ripper: Fixed erred token on wrong alias [Bug #17345]

parse.y

@@ -607,6 +607,7 @@ static ID ripper_get_id(VALUE);
 static VALUE ripper_get_value(VALUE);
 #define get_value(val) ripper_get_value(val)
 #define get_num(num) (int)get_id(num)
+#define get_cval(val) RNODE(val)->nd_cval
 static VALUE assignable(struct parser_params*,VALUE);
 static int id_is_var(struct parser_params *p, ID id);
 
@@ -1461,7 +1462,7 @@ stmt		: keyword_alias fitem {SET_LEX_STATE(EXPR_FNAME|EXPR_FITEM);} fitem
 			yyerror1(&@3, mesg);
 			$$ = NEW_BEGIN(0, &@$);
 		    /*% %*/
-		    /*% ripper[error]: alias_error!(ERR_MESG(), var_alias!($2, $3)) %*/
+		    /*% ripper[error]: alias_error!(ERR_MESG(), get_cval($3)) %*/
 		    }
 		| keyword_undef undef_list
 		    {

test/ripper/test_parser_events.rb

@@ -96,7 +96,7 @@ class TestRipper::ParserEvents < Test::Unit::TestCase
   end
 
   def test_alias_error
-    assert_equal '[aliaserr(valias($a,$1))]', parse('alias $a $1')
+    assert_equal '[aliaserr($1)]', parse('alias $a $1')
   end
 
   def test_arglist