1 files changed, 5 insertions, 18 deletions

diff --git a/activesupport/lib/active_support/callbacks.rb b/activesupport/lib/active_support/callbacks.rb
index 4e319b4bba..a9253c186d 100644
--- a/activesupport/lib/active_support/callbacks.rb
+++ b/activesupport/lib/active_support/callbacks.rb
@@ -310,13 +310,13 @@ module ActiveSupport
         method << "value = nil"
         method << "halted = false"
 
-        callbacks = "value = yield if block_given? && !halted"
+        callbacks = "value = !halted && (!block_given? || yield)"
         reverse_each do |callback|
           callbacks = callback.apply(callbacks)
         end
         method << callbacks
 
-        method << "halted ? false : (block_given? ? value : true)"
+        method << "value"
         method.join("\n")
       end
 
@@ -328,26 +328,17 @@ module ActiveSupport
       # if it was not yet defined.
       # This generated method plays caching role.
       def __define_callbacks(kind, object) #:nodoc:
-        name = __callback_runner_name(kind)
+        chain = object.send("_#{kind}_callbacks")
+        name = "_run_callbacks_#{chain.object_id.abs}"
         unless object.respond_to?(name, true)
-          str = object.send("_#{kind}_callbacks").compile
           class_eval <<-RUBY_EVAL, __FILE__, __LINE__ + 1
-            def #{name}() #{str} end
+            def #{name}() #{chain.compile} end
             protected :#{name}
           RUBY_EVAL
         end
         name
       end
 
-      def __reset_runner(symbol)
-        name = __callback_runner_name(symbol)
-        undef_method(name) if method_defined?(name)
-      end
-
-      def __callback_runner_name(kind)
-        "_run__#{self.name.hash.abs}__#{kind}__callbacks"
-      end
-
       # This is used internally to append, prepend and skip callbacks to the
       # CallbackChain.
       #
@@ -359,7 +350,6 @@ module ActiveSupport
         ([self] + ActiveSupport::DescendantsTracker.descendants(self)).reverse.each do |target|
           chain = target.send("_#{name}_callbacks")
           yield target, chain.dup, type, filters, options
-          target.__reset_runner(name)
         end
       end
 
@@ -447,12 +437,9 @@ module ActiveSupport
           chain = target.send("_#{symbol}_callbacks").dup
           callbacks.each { |c| chain.delete(c) }
           target.send("_#{symbol}_callbacks=", chain)
-          target.__reset_runner(symbol)
         end
 
         self.send("_#{symbol}_callbacks=", callbacks.dup.clear)
-
-        __reset_runner(symbol)
       end
 
       # Define sets of events in the object lifecycle that support callbacks.