1 files changed, 19 insertions, 4 deletions
diff --git a/spec/ruby/core/array/rindex_spec.rb b/spec/ruby/core/array/rindex_spec.rb
index 19a6f04c85..13de88818c 100644
--- a/spec/ruby/core/array/rindex_spec.rb
+++ b/spec/ruby/core/array/rindex_spec.rb
@@ -1,10 +1,10 @@
-require File.expand_path('../../../spec_helper', __FILE__)
-require File.expand_path('../fixtures/classes', __FILE__)
-require File.expand_path('../../enumerable/shared/enumeratorized', __FILE__)
+require_relative '../../spec_helper'
+require_relative 'fixtures/classes'
+require_relative '../enumerable/shared/enumeratorized'
 
 # Modifying a collection while the contents are being iterated
 # gives undefined behavior. See
-# http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/23633
+# https://blade.ruby-lang.org/ruby-core/23633
 
 describe "Array#rindex" do
   it "returns the first index backwards from the end where element == to object" do
@@ -68,6 +68,21 @@ describe "Array#rindex" do
     seen.should == [3]
   end
 
+  it "tolerates increasing an array size during iteration" do
+    array = [:a, :b, :c]
+    ScratchPad.record []
+    i = 0
+
+    array.rindex do |e|
+      ScratchPad << e
+      array.prepend i if i < 100
+      i += 1
+      false
+    end
+
+    ScratchPad.recorded.should == [:c, :a, 1]
+  end
+
   describe "given no argument and no block" do
     it "produces an Enumerator" do
       enum = [4, 2, 1, 5, 1, 3].rindex