From 5e8186a8ce680894547112d43da3781b9e1c0793 Mon Sep 17 00:00:00 2001
From: Merlyn Morgan-Graham <kavika@gmail.com>
Date: Mon, 9 Dec 2019 22:56:21 -0800
Subject: [PATCH] Fix access of undefined field when calling ast.Tree.dump

---
 lib/std/zig/ast.zig | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/std/zig/ast.zig b/lib/std/zig/ast.zig
index 5fa519aa90..ffa8f434a3 100644
--- a/lib/std/zig/ast.zig
+++ b/lib/std/zig/ast.zig
@@ -967,7 +967,9 @@ pub const Node = struct {
         pub fn iterate(self: *ParamDecl, index: usize) ?*Node {
             var i = index;
 
-            if (i < 1) return self.type_node;
+            if (i < 1) {
+                return if (self.var_args_token == null) self.type_node else null;
+            }
             i -= 1;
 
             return null;