add Hash#rehash to handle key modification; ref #2945

1 files changed, 23 insertions, 0 deletions

diff --git a/mrblib/hash.rb b/mrblib/hash.rb
index cb52c1ffe..48ac96e56 100644
--- a/mrblib/hash.rb
+++ b/mrblib/hash.rb
@@ -319,6 +319,29 @@ class Hash
     h
   end
 
+  ##
+  #  call-seq:
+  #    hsh.rehash -> hsh
+  #
+  #  Rebuilds the hash based on the current hash values for each key. If
+  #  values of key objects have changed since they were inserted, this
+  #  method will reindex <i>hsh</i>.
+  #
+  #     h = {"AAA" => "b"}
+  #     h.keys[0].chop!
+  #     h          #=> {"AA"=>"b"}
+  #     h["AA"]    #=> nil
+  #     h.rehash   #=> {"AA"=>"b"}
+  #     h["AA"]    #=> "b"
+  #
+  def rehash
+    h = {}
+    self.each{|k,v|
+      h[k] = v
+    }
+    self.replace(h)
+  end
+
   def __update(h)
     h.each_key{|k| self[k] = h[k]}
     self