From e95cac18bd9648aa023e390a716c5887155b72b7 Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Fri, 12 May 2017 17:02:48 +0000
Subject: [PATCH] array.c: check position to insert

* array.c (rb_ary_insert): check position to insert even if no
  elements to be inserted.  [ruby-core:81125] [Bug #13558]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58693 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 array.c                 | 2 +-
 test/ruby/test_array.rb | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/array.c b/array.c
index e21c01194c..1eb1d2ea35 100644
--- a/array.c
+++ b/array.c
@@ -1781,8 +1781,8 @@ rb_ary_insert(int argc, VALUE *argv, VALUE ary)
 
     rb_check_arity(argc, 1, UNLIMITED_ARGUMENTS);
     rb_ary_modify_check(ary);
-    if (argc == 1) return ary;
     pos = NUM2LONG(argv[0]);
+    if (argc == 1) return ary;
     if (pos == -1) {
 	pos = RARRAY_LEN(ary);
     }
diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb
index d797ee8164..60938937cd 100644
--- a/test/ruby/test_array.rb
+++ b/test/ruby/test_array.rb
@@ -2121,6 +2121,7 @@ class TestArray < Test::Unit::TestCase
     assert_equal([0], a.insert(1))
     assert_equal([0, 1], a.insert(1, 1))
     assert_raise(ArgumentError) { a.insert }
+    assert_raise(TypeError) { a.insert(Object.new) }
     assert_equal([0, 1, 2], a.insert(-1, 2))
     assert_equal([0, 1, 3, 2], a.insert(-2, 3))
     assert_raise(RuntimeError) { [0].freeze.insert(0)}