Fix Hash.shift (3.2)

README.md

@@ -119,6 +119,10 @@ itself, JRuby and Rubinius.
 
 - `Enumerator.product` and `Enumerator::Product`
 
+#### Hash
+
+- `shift` (with correct behavior when empty)
+
 ## Ruby 3.1 backports
 
 #### Array

Rakefile

@@ -140,6 +140,7 @@ IGNORE = %w[
   3.1.0/enumerable/compact
   3.1.0/struct/keyword_init
   3.2.0/enumerator/product
+  3.2.0/hash/shift
 ]
 
 CLASS_MAP = Hash.new{|k, v| k[v] = v}.merge!(

lib/backports/3.2.0/hash.rb

@@ -0,0 +1,3 @@
+require 'backports/tools/require_relative_dir'
+
+Backports.require_relative_dir

lib/backports/3.2.0/hash/shift.rb

@@ -0,0 +1,10 @@
+if Hash.new(42).shift
+  require 'backports/tools/alias_method_chain'
+
+  class Hash
+    def shift_with_correct_behaviour_when_empty
+      shift_without_correct_behaviour_when_empty unless empty?
+    end
+    Backports.alias_method_chain self, :shift, :correct_behaviour_when_empty
+  end
+end