fix method redefined

Author: david942j

Gemfile.lock

@@ -26,7 +26,7 @@ GEM
       slop (~> 3.4)
     rainbow (2.2.2)
       rake
-    rake (12.0.0)
+    rake (12.1.0)
     rspec (3.6.0)
       rspec-core (~> 3.6.0)
       rspec-expectations (~> 3.6.0)
@@ -64,7 +64,7 @@ DEPENDENCIES
   codeclimate-test-reporter (~> 0.6)
   elftools!
   pry (~> 0.10)
-  rake (~> 12.0)
+  rake (~> 12.1)
   rspec (~> 3.5)
   rubocop (~> 0.47)
   simplecov (~> 0.13.0)

elftools.gemspec

@@ -23,7 +23,7 @@ Gem::Specification.new do |s|
 
   s.add_development_dependency 'codeclimate-test-reporter', '~> 0.6'
   s.add_development_dependency 'pry', '~> 0.10'
-  s.add_development_dependency 'rake', '~> 12.0'
+  s.add_development_dependency 'rake', '~> 12.1'
   s.add_development_dependency 'rspec', '~> 3.5'
   s.add_development_dependency 'rubocop', '~> 0.47'
   s.add_development_dependency 'simplecov', '~> 0.13.0'

lib/elftools/structs.rb

@@ -32,6 +32,7 @@ def new(**kwargs)
             obj.field_names.each do |f|
               m = "#{f}=".to_sym
               old_method = obj.singleton_method(m)
+              obj.singleton_class.send(:undef_method, m)
               obj.define_singleton_method(m) do |val|
                 org = obj.send(f)
                 obj.patches[org.abs_offset] = ELFStruct.pack(val, org.num_bytes)