Merge remote branch 'mainstream/master'

Conflicts:
	railties/README
	railties/guides/source/active_support_core_extensions.textile
	railties/guides/source/getting_started.textile
	railties/lib/generators/rails/app/templates/README

21 files changed, 310 insertions, 274 deletions

diff --git a/activesupport/lib/active_support/core_ext/class.rb b/activesupport/lib/active_support/core_ext/class.rb
index 62df7d8b82..f2ca9c7cc9 100644
--- a/activesupport/lib/active_support/core_ext/class.rb
+++ b/activesupport/lib/active_support/core_ext/class.rb
@@ -1,3 +1,4 @@
 require 'active_support/core_ext/class/attribute_accessors'
 require 'active_support/core_ext/class/inheritable_attributes'
 require 'active_support/core_ext/class/delegating_attributes'
+require 'active_support/core_ext/class/subclasses'
diff --git a/activesupport/lib/active_support/core_ext/class/subclasses.rb b/activesupport/lib/active_support/core_ext/class/subclasses.rb
new file mode 100644
index 0000000000..bbd8f5aef6
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/class/subclasses.rb
@@ -0,0 +1,55 @@
+require 'active_support/core_ext/module/anonymous'
+require 'active_support/core_ext/module/reachable'
+
+class Class #:nodoc:
+  # Returns an array with the names of the subclasses of +self+ as strings.
+  #
+  #   Integer.subclasses # => ["Bignum", "Fixnum"]
+  def subclasses
+    Class.subclasses_of(self).map { |o| o.to_s }
+  end
+
+  # Rubinius
+  if defined?(Class.__subclasses__)
+    def descendents
+      subclasses = []
+      __subclasses__.each {|k| subclasses << k; subclasses.concat k.descendents }
+      subclasses
+    end
+  else
+    # MRI
+    begin
+      ObjectSpace.each_object(Class.new) {}
+
+      def descendents
+        subclasses = []
+        ObjectSpace.each_object(class << self; self; end) do |k|
+          subclasses << k unless k == self
+        end
+        subclasses
+      end
+    # JRuby
+    rescue StandardError
+      def descendents
+        subclasses = []
+        ObjectSpace.each_object(Class) do |k|
+          subclasses << k if k < self
+        end
+        subclasses.uniq!
+        subclasses
+      end
+    end
+  end
+
+  # Exclude this class unless it's a subclass of our supers and is defined.
+  # We check defined? in case we find a removed class that has yet to be
+  # garbage collected. This also fails for anonymous classes -- please
+  # submit a patch if you have a workaround.
+  def self.subclasses_of(*superclasses) #:nodoc:
+    subclasses = []
+    superclasses.each do |klass|
+      subclasses.concat klass.descendents.select {|k| k.anonymous? || k.reachable?}
+    end
+    subclasses
+  end
+end
diff --git a/activesupport/lib/active_support/core_ext/file/atomic.rb b/activesupport/lib/active_support/core_ext/file/atomic.rb
index 249fb1362d..49d28e8a34 100644
--- a/activesupport/lib/active_support/core_ext/file/atomic.rb
+++ b/activesupport/lib/active_support/core_ext/file/atomic.rb
@@ -9,7 +9,7 @@ class File
   # If your temp directory is not on the same filesystem as the file you're
   # trying to write, you can provide a different temporary directory.
   #
-  #   File.atomic_write("/data/something.important", "/data/tmp") do |f|
+  #   File.atomic_write("/data/something.important", "/data/tmp") do |file|
   #     file.write("hello")
   #   end
   def self.atomic_write(file_name, temp_dir = Dir.tmpdir)
diff --git a/activesupport/lib/active_support/core_ext/kernel.rb b/activesupport/lib/active_support/core_ext/kernel.rb
index 1922d804bf..c3bed14f63 100644
--- a/activesupport/lib/active_support/core_ext/kernel.rb
+++ b/activesupport/lib/active_support/core_ext/kernel.rb
@@ -1,4 +1,3 @@
-require 'active_support/core_ext/kernel/daemonizing'
 require 'active_support/core_ext/kernel/reporting'
 require 'active_support/core_ext/kernel/agnostics'
 require 'active_support/core_ext/kernel/requires'
diff --git a/activesupport/lib/active_support/core_ext/kernel/daemonizing.rb b/activesupport/lib/active_support/core_ext/kernel/daemonizing.rb
deleted file mode 100644
index ed9d1f9bf2..0000000000
--- a/activesupport/lib/active_support/core_ext/kernel/daemonizing.rb
+++ /dev/null
@@ -1,7 +0,0 @@
-module Kernel
-  # Turns the current script into a daemon process that detaches from the console.
-  # It can be shut down with a TERM signal.
-  def daemonize
-    Process.daemon
-  end
-end
diff --git a/activesupport/lib/active_support/core_ext/kernel/debugger.rb b/activesupport/lib/active_support/core_ext/kernel/debugger.rb
index 59e03e3df7..22fcc1910b 100644
--- a/activesupport/lib/active_support/core_ext/kernel/debugger.rb
+++ b/activesupport/lib/active_support/core_ext/kernel/debugger.rb
@@ -1,6 +1,6 @@
 module Kernel
   unless respond_to?(:debugger)
-    # Starts a debugging session if ruby-debug has been loaded (call script/server --debugger to do load it).
+    # Starts a debugging session if ruby-debug has been loaded (call rails server --debugger to do load it).
     def debugger
       message = "\n***** Debugger requested, but was not available: Start server with --debugger to enable *****\n"
       defined?(Rails) ? Rails.logger.info(message) : $stderr.puts(message)
diff --git a/activesupport/lib/active_support/core_ext/module.rb b/activesupport/lib/active_support/core_ext/module.rb
index fbe89fe07c..bf272e9e73 100644
--- a/activesupport/lib/active_support/core_ext/module.rb
+++ b/activesupport/lib/active_support/core_ext/module.rb
@@ -1,10 +1,10 @@
 require 'active_support/core_ext/module/aliasing'
 require 'active_support/core_ext/module/introspection'
-
-require 'active_support/core_ext/module/inclusion'
+require 'active_support/core_ext/module/anonymous'
+require 'active_support/core_ext/module/reachable'
 require 'active_support/core_ext/module/attribute_accessors'
 require 'active_support/core_ext/module/attr_internal'
 require 'active_support/core_ext/module/attr_accessor_with_default'
 require 'active_support/core_ext/module/delegation'
-require 'active_support/core_ext/module/loading'
 require 'active_support/core_ext/module/synchronization'
+require 'active_support/core_ext/module/deprecation'
\ No newline at end of file
diff --git a/activesupport/lib/active_support/core_ext/module/anonymous.rb b/activesupport/lib/active_support/core_ext/module/anonymous.rb
new file mode 100644
index 0000000000..df25a09ec9
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/module/anonymous.rb
@@ -0,0 +1,24 @@
+require 'active_support/core_ext/object/blank'
+
+class Module
+  # A module may or may not have a name.
+  #
+  #   module M; end
+  #   M.name # => "M"
+  #
+  #   m = Module.new
+  #   m.name # => ""
+  #
+  # A module gets a name when it is first assigned to a constant. Either
+  # via the +module+ or +class+ keyword or by an explicit assignment:
+  #
+  #   m = Module.new # creates an anonymous module
+  #   M = m          # => m gets a name here as a side-effect
+  #   m.name         # => "M"
+  #
+  def anonymous?
+    # Uses blank? because the name of an anonymous class is an empty
+    # string in 1.8, and nil in 1.9.
+    name.blank? 
+  end
+end
diff --git a/activesupport/lib/active_support/core_ext/module/inclusion.rb b/activesupport/lib/active_support/core_ext/module/inclusion.rb
deleted file mode 100644
index 4f23841645..0000000000
--- a/activesupport/lib/active_support/core_ext/module/inclusion.rb
+++ /dev/null
@@ -1,30 +0,0 @@
-class Module
-  # Returns the classes in the current ObjectSpace where this module has been
-  # mixed in according to Module#included_modules.
-  #
-  #   module M
-  #   end
-  #   
-  #   module N
-  #     include M
-  #   end
-  #   
-  #   class C
-  #     include M
-  #   end
-  #   
-  #   class D < C
-  #   end
-  #
-  #   p M.included_in_classes # => [C, D]
-  #
-  def included_in_classes
-    classes = []
-    ObjectSpace.each_object(Class) { |k| classes << k if k.included_modules.include?(self) }
-
-    classes.reverse.inject([]) do |unique_classes, klass| 
-      unique_classes << klass unless unique_classes.collect { |k| k.to_s }.include?(klass.to_s)
-      unique_classes
-    end
-  end
-end
\ No newline at end of file
diff --git a/activesupport/lib/active_support/core_ext/module/loading.rb b/activesupport/lib/active_support/core_ext/module/loading.rb
deleted file mode 100644
index 43d0578ae6..0000000000
--- a/activesupport/lib/active_support/core_ext/module/loading.rb
+++ /dev/null
@@ -1,25 +0,0 @@
-require 'active_support/core_ext/string/inflections'
-
-class Module
-  # Returns String#underscore applied to the module name minus trailing classes.
-  #
-  #   ActiveRecord.as_load_path               # => "active_record"
-  #   ActiveRecord::Associations.as_load_path # => "active_record/associations"
-  #   ActiveRecord::Base.as_load_path         # => "active_record" (Base is a class)
-  #
-  # The Kernel module gives an empty string by definition.
-  #
-  #   Kernel.as_load_path # => ""
-  #   Math.as_load_path   # => "math"
-  def as_load_path
-    if self == Object || self == Kernel
-      ''
-    elsif is_a? Class
-      parent == self ? '' : parent.as_load_path
-    else
-      name.split('::').collect do |word|
-        word.underscore
-      end * '/'
-    end
-  end
-end
\ No newline at end of file
diff --git a/activesupport/lib/active_support/core_ext/module/reachable.rb b/activesupport/lib/active_support/core_ext/module/reachable.rb
new file mode 100644
index 0000000000..443d2c3d53
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/module/reachable.rb
@@ -0,0 +1,10 @@
+require 'active_support/core_ext/module/anonymous'
+require 'active_support/core_ext/string/inflections'
+
+class Module
+  def reachable? #:nodoc:
+    !anonymous? && name.constantize.equal?(self)
+  rescue NameError
+    false
+  end
+end
diff --git a/activesupport/lib/active_support/core_ext/object.rb b/activesupport/lib/active_support/core_ext/object.rb
index 08e07a5b24..db2dac1472 100644
--- a/activesupport/lib/active_support/core_ext/object.rb
+++ b/activesupport/lib/active_support/core_ext/object.rb
@@ -7,3 +7,9 @@ require 'active_support/core_ext/object/conversions'
 require 'active_support/core_ext/object/instance_variables'
 require 'active_support/core_ext/object/metaclass'
 require 'active_support/core_ext/object/misc'
+require 'active_support/core_ext/object/extending'
+
+require 'active_support/core_ext/object/returning'
+require 'active_support/core_ext/object/to_param'
+require 'active_support/core_ext/object/to_query'
+require 'active_support/core_ext/object/with_options'
diff --git a/activesupport/lib/active_support/core_ext/object/extending.rb b/activesupport/lib/active_support/core_ext/object/extending.rb
new file mode 100644
index 0000000000..c4c37b6a2a
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/object/extending.rb
@@ -0,0 +1,11 @@
+require 'active_support/core_ext/class/subclasses'
+
+class Object
+  # Exclude this class unless it's a subclass of our supers and is defined.
+  # We check defined? in case we find a removed class that has yet to be
+  # garbage collected. This also fails for anonymous classes -- please
+  # submit a patch if you have a workaround.
+  def subclasses_of(*superclasses) #:nodoc:
+    Class.subclasses_of(*superclasses)
+  end
+end
diff --git a/activesupport/lib/active_support/core_ext/string/output_safety.rb b/activesupport/lib/active_support/core_ext/string/output_safety.rb
index 3977971e8d..567ba00b0d 100644
--- a/activesupport/lib/active_support/core_ext/string/output_safety.rb
+++ b/activesupport/lib/active_support/core_ext/string/output_safety.rb
@@ -71,15 +71,12 @@ module ActiveSupport #:nodoc:
         super(ERB::Util.h(value))
       end
     end
+    alias << concat
 
     def +(other)
       dup.concat(other)
     end
 
-    def <<(value)
-      self.concat(value)
-    end
-
     def html_safe?
       true
     end
@@ -102,4 +99,4 @@ class String
   def html_safe
     ActiveSupport::SafeBuffer.new(self)
   end
-end
\ No newline at end of file
+end
diff --git a/activesupport/lib/active_support/core_ext/string/xchar.rb b/activesupport/lib/active_support/core_ext/string/xchar.rb
index 7183218634..f9a5b4fb64 100644
--- a/activesupport/lib/active_support/core_ext/string/xchar.rb
+++ b/activesupport/lib/active_support/core_ext/string/xchar.rb
@@ -1,5 +1,5 @@
 begin
-  # See http://bogomips.org/fast_xs/ by Eric Wong.
+  # See http://fast-xs.rubyforge.org/ by Eric Wong.
   # Also included with hpricot.
   require 'fast_xs'
 rescue LoadError
diff --git a/activesupport/lib/active_support/dependencies.rb b/activesupport/lib/active_support/dependencies.rb
index 8ded9f8b2d..56de29b730 100644
--- a/activesupport/lib/active_support/dependencies.rb
+++ b/activesupport/lib/active_support/dependencies.rb
@@ -1,8 +1,10 @@
 require 'set'
 require 'thread'
+require 'pathname'
 require 'active_support/core_ext/module/aliasing'
 require 'active_support/core_ext/module/attribute_accessors'
 require 'active_support/core_ext/module/introspection'
+require 'active_support/core_ext/module/anonymous'
 require 'active_support/core_ext/object/blank'
 require 'active_support/core_ext/load_error'
 require 'active_support/core_ext/name_error'
@@ -58,85 +60,116 @@ module ActiveSupport #:nodoc:
     mattr_accessor :log_activity
     self.log_activity = false
 
+    class WatchStack < Array
+      def initialize
+        @mutex = Mutex.new
+      end
+
+      def self.locked(*methods)
+        methods.each { |m| class_eval "def #{m}(*) lock { super } end" }
+      end
+
+      def get(key)
+        (val = assoc(key)) ? val[1] : []
+      end
+
+      locked :concat, :each, :delete_if, :<<
+
+      def new_constants_for(frames)
+        frames.map do |mod_name, prior_constants|
+          mod = Inflector.constantize(mod_name)
+          next unless mod.is_a?(Module)
+
+          new_constants = mod.local_constant_names - prior_constants
+          get(mod_name).concat(new_constants)
+
+          new_constants.map do |suffix|
+            ([mod_name, suffix] - ["Object"]).join("::")
+          end
+        end.flatten
+      end
+
+      # Add a set of modules to the watch stack, remembering the initial constants
+      def add_modules(modules)
+        list = modules.map do |desc|
+          name = Dependencies.to_constant_name(desc)
+          consts = Dependencies.qualified_const_defined?(name) ?
+            Inflector.constantize(name).local_constant_names : []
+          [name, consts]
+        end
+        concat(list)
+        list
+      end
+
+      def lock
+        @mutex.synchronize { yield self }
+      end
+    end
+
     # An internal stack used to record which constants are loaded by any block.
     mattr_accessor :constant_watch_stack
-    self.constant_watch_stack = []
-
-    mattr_accessor :constant_watch_stack_mutex
-    self.constant_watch_stack_mutex = Mutex.new
+    self.constant_watch_stack = WatchStack.new
 
     # Module includes this module
     module ModuleConstMissing #:nodoc:
-      def self.included(base) #:nodoc:
+      def self.append_features(base)
         base.class_eval do
-          unless defined? const_missing_without_dependencies
-            alias_method_chain :const_missing, :dependencies
-          end
+          # Emulate #exclude via an ivar
+          return if @_const_missing
+          @_const_missing = method(:const_missing)
+          remove_method(:const_missing)
         end
+        super
       end
 
-      def self.excluded(base) #:nodoc:
+      def self.exclude_from(base)
         base.class_eval do
-          if defined? const_missing_without_dependencies
-            undef_method :const_missing
-            alias_method :const_missing, :const_missing_without_dependencies
-            undef_method :const_missing_without_dependencies
-          end
+          define_method :const_missing, @_const_missing
+          @_const_missing = nil
         end
       end
 
       # Use const_missing to autoload associations so we don't have to
       # require_association when using single-table inheritance.
-      def const_missing_with_dependencies(class_id)
-        ActiveSupport::Dependencies.load_missing_constant self, class_id
-      end
+      def const_missing(const_name, nesting = nil)
+        klass_name = name.presence || "Object"
+
+        if !nesting
+          # We'll assume that the nesting of Foo::Bar is ["Foo::Bar", "Foo"]
+          # even though it might not be, such as in the case of
+          # class Foo::Bar; Baz; end
+          nesting = []
+          klass_name.to_s.scan(/::|$/) { nesting.unshift $` }
+        end
 
-      def unloadable(const_desc = self)
-        super(const_desc)
-      end
-    end
+        # If there are multiple levels of nesting to search under, the top
+        # level is the one we want to report as the lookup fail.
+        error = nil
 
-    # Class includes this module
-    module ClassConstMissing #:nodoc:
-      def const_missing(const_name)
-        if [Object, Kernel].include?(self) || parent == self
-          super
-        else
+        nesting.each do |namespace|
           begin
-            begin
-              Dependencies.load_missing_constant self, const_name
-            rescue NameError
-              parent.send :const_missing, const_name
-            end
+            return Dependencies.load_missing_constant namespace.constantize, const_name
+          rescue NoMethodError then raise
           rescue NameError => e
-            # Make sure that the name we are missing is the one that caused the error
-            parent_qualified_name = Dependencies.qualified_name_for parent, const_name
-            raise unless e.missing_name? parent_qualified_name
-            qualified_name = Dependencies.qualified_name_for self, const_name
-            raise NameError.new("uninitialized constant #{qualified_name}").copy_blame!(e)
+            error ||= e
           end
         end
+
+        # Raise the first error for this set. If this const_missing came from an
+        # earlier const_missing, this will result in the real error bubbling
+        # all the way up
+        raise error
+      end
+
+      def unloadable(const_desc = self)
+        super(const_desc)
       end
     end
 
     # Object includes this module
     module Loadable #:nodoc:
-      def self.included(base) #:nodoc:
-        base.class_eval do
-          unless defined? load_without_new_constant_marking
-            alias_method_chain :load, :new_constant_marking
-          end
-        end
-      end
-
-      def self.excluded(base) #:nodoc:
-        base.class_eval do
-          if defined? load_without_new_constant_marking
-            undef_method :load
-            alias_method :load, :load_without_new_constant_marking
-            undef_method :load_without_new_constant_marking
-          end
-        end
+      def self.exclude_from(base)
+        base.class_eval { define_method(:load, Kernel.instance_method(:load)) }
       end
 
       def require_or_load(file_name)
@@ -151,26 +184,23 @@ module ActiveSupport #:nodoc:
         Dependencies.associate_with(file_name)
       end
 
-      def load_with_new_constant_marking(file, *extras) #:nodoc:
+      def load_dependency(file)
         if Dependencies.load?
-          Dependencies.new_constants_in(Object) { load_without_new_constant_marking(file, *extras) }
+          Dependencies.new_constants_in(Object) { yield }.presence
         else
-          load_without_new_constant_marking(file, *extras)
+          yield
         end
       rescue Exception => exception  # errors from loading file
         exception.blame_file! file
         raise
       end
 
-      def require(file, *extras) #:nodoc:
-        if Dependencies.load?
-          Dependencies.new_constants_in(Object) { super }
-        else
-          super
-        end
-      rescue Exception => exception  # errors from required file
-        exception.blame_file! file
-        raise
+      def load(file, *)
+        load_dependency(file) { super }
+      end
+
+      def require(file, *)
+        load_dependency(file) { super }
       end
 
       # Mark the given constant as unloadable. Unloadable constants are removed each
@@ -213,16 +243,15 @@ module ActiveSupport #:nodoc:
     end
 
     def hook!
-      Object.instance_eval { include Loadable }
-      Module.instance_eval { include ModuleConstMissing }
-      Class.instance_eval { include ClassConstMissing }
-      Exception.instance_eval { include Blamable }
+      Object.class_eval { include Loadable }
+      Module.class_eval { include ModuleConstMissing }
+      Exception.class_eval { include Blamable }
       true
     end
 
     def unhook!
-      ModuleConstMissing.excluded(Module)
-      Loadable.excluded(Object)
+      ModuleConstMissing.exclude_from(Module)
+      Loadable.exclude_from(Object)
       true
     end
 
@@ -292,29 +321,22 @@ module ActiveSupport #:nodoc:
 
     # Is the provided constant path defined?
     def qualified_const_defined?(path)
-      raise NameError, "#{path.inspect} is not a valid constant name!" unless
-        /^(::)?([A-Z]\w*)(::[A-Z]\w*)*$/ =~ path
-
-      names = path.to_s.split('::')
-      names.shift if names.first.empty?
+      names = path.sub(/^::/, '').to_s.split('::')
 
-      # We can't use defined? because it will invoke const_missing for the parent
-      # of the name we are checking.
       names.inject(Object) do |mod, name|
-        return false unless uninherited_const_defined?(mod, name)
+        return false unless local_const_defined?(mod, name)
         mod.const_get name
       end
-      return true
     end
 
     if Module.method(:const_defined?).arity == 1
       # Does this module define this constant?
       # Wrapper to accomodate changing Module#const_defined? in Ruby 1.9
-      def uninherited_const_defined?(mod, const)
+      def local_const_defined?(mod, const)
         mod.const_defined?(const)
       end
     else
-      def uninherited_const_defined?(mod, const) #:nodoc:
+      def local_const_defined?(mod, const) #:nodoc:
         mod.const_defined?(const, false)
       end
     end
@@ -322,29 +344,20 @@ module ActiveSupport #:nodoc:
     # Given +path+, a filesystem path to a ruby file, return an array of constant
     # paths which would cause Dependencies to attempt to load this file.
     def loadable_constants_for_path(path, bases = load_paths)
-      path = $1 if path =~ /\A(.*)\.rb\Z/
-      expanded_path = File.expand_path(path)
-
-      bases.collect do |root|
-        expanded_root = File.expand_path(root)
-        next unless %r{\A#{Regexp.escape(expanded_root)}(/|\\)} =~ expanded_path
-
-        nesting = expanded_path[(expanded_root.size)..-1]
-        nesting = nesting[1..-1] if nesting && nesting[0] == ?/
-        next if nesting.blank?
-        nesting_camel = nesting.camelize
-        begin
-          qualified_const_defined?(nesting_camel)
-        rescue NameError
-          next
-        end
-        [ nesting_camel ]
-      end.compact.flatten.compact.uniq
+      expanded_path = Pathname.new(path[/\A(.*?)(\.rb)?\Z/, 1]).expand_path
+
+      bases.inject([]) do |paths, root|
+        expanded_root = Pathname.new(root).expand_path
+        nesting = expanded_path.relative_path_from(expanded_root).to_s
+        next paths if nesting =~ /\.\./
+        paths << nesting.camelize
+      end.uniq
     end
 
     # Search for a file in load_paths matching the provided suffix.
     def search_for_file(path_suffix)
-      path_suffix = "#{path_suffix}.rb" unless path_suffix =~ /\.rb\Z/
+      path_suffix = path_suffix.sub(/(\.rb)?$/, ".rb")
+
       load_paths.each do |root|
         path = File.join(root, path_suffix)
         return path if File.file? path
@@ -393,7 +406,7 @@ module ActiveSupport #:nodoc:
 
       result = nil
       newly_defined_paths = new_constants_in(*parent_paths) do
-        result = load_without_new_constant_marking path
+        result = Kernel.load path
       end
 
       autoloaded_constants.concat newly_defined_paths unless load_once_path?(path)
@@ -405,7 +418,7 @@ module ActiveSupport #:nodoc:
     # Return the constant path for the provided parent and constant name.
     def qualified_name_for(mod, name)
       mod_name = to_constant_name mod
-      (%w(Object Kernel).include? mod_name) ? name.to_s : "#{mod_name}::#{name}"
+      mod_name == "Object" ? name.to_s : "#{mod_name}::#{name}"
     end
 
     # Load the constant named +const_name+ which is missing from +from_mod+. If
@@ -413,38 +426,27 @@ module ActiveSupport #:nodoc:
     # using const_missing.
     def load_missing_constant(from_mod, const_name)
       log_call from_mod, const_name
-      if from_mod == Kernel
-        if ::Object.const_defined?(const_name)
-          log "Returning Object::#{const_name} for Kernel::#{const_name}"
-          return ::Object.const_get(const_name)
-        else
-          log "Substituting Object for Kernel"
-          from_mod = Object
-        end
-      end
-
-      # If we have an anonymous module, all we can do is attempt to load from Object.
-      from_mod = Object if from_mod.name.blank?
 
-      unless qualified_const_defined?(from_mod.name) && Inflector.constantize(from_mod.name).object_id == from_mod.object_id
+      unless qualified_const_defined?(from_mod.name) && Inflector.constantize(from_mod.name).equal?(from_mod)
         raise ArgumentError, "A copy of #{from_mod} has been removed from the module tree but is still active!"
       end
 
-      raise ArgumentError, "#{from_mod} is not missing constant #{const_name}!" if uninherited_const_defined?(from_mod, const_name)
+      raise ArgumentError, "#{from_mod} is not missing constant #{const_name}!" if local_const_defined?(from_mod, const_name)
 
       qualified_name = qualified_name_for from_mod, const_name
       path_suffix = qualified_name.underscore
       name_error = NameError.new("uninitialized constant #{qualified_name}")
 
       file_path = search_for_file(path_suffix)
+
       if file_path && ! loaded.include?(File.expand_path(file_path)) # We found a matching file to load
         require_or_load file_path
-        raise LoadError, "Expected #{file_path} to define #{qualified_name}" unless uninherited_const_defined?(from_mod, const_name)
+        raise LoadError, "Expected #{file_path} to define #{qualified_name}" unless local_const_defined?(from_mod, const_name)
         return from_mod.const_get(const_name)
       elsif mod = autoload_module!(from_mod, const_name, qualified_name, path_suffix)
         return mod
       elsif (parent = from_mod.parent) && parent != from_mod &&
-            ! from_mod.parents.any? { |p| uninherited_const_defined?(p, const_name) }
+            ! from_mod.parents.any? { |p| local_const_defined?(p, const_name) }
         # If our parents do not have a constant named +const_name+ then we are free
         # to attempt to load upwards. If they do have such a constant, then this
         # const_missing must be due to from_mod::const_name, which should not
@@ -471,7 +473,7 @@ module ActiveSupport #:nodoc:
     # Determine if the given constant has been automatically loaded.
     def autoloaded?(desc)
       # No name => anonymous module.
-      return false if desc.is_a?(Module) && desc.name.blank?
+      return false if desc.is_a?(Module) && desc.anonymous?
       name = to_constant_name desc
       return false unless qualified_const_defined? name
       return autoloaded_constants.include?(name)
@@ -505,79 +507,26 @@ module ActiveSupport #:nodoc:
     # and will be removed immediately.
     def new_constants_in(*descs)
       log_call(*descs)
-
-      # Build the watch frames. Each frame is a tuple of
-      #   [module_name_as_string, constants_defined_elsewhere]
-      watch_frames = descs.collect do |desc|
-        if desc.is_a? Module
-          mod_name = desc.name
-          initial_constants = desc.local_constant_names
-        elsif desc.is_a?(String) || desc.is_a?(Symbol)
-          mod_name = desc.to_s
-
-          # Handle the case where the module has yet to be defined.
-          initial_constants = if qualified_const_defined?(mod_name)
-            Inflector.constantize(mod_name).local_constant_names
-          else
-            []
-          end
-        else
-          raise Argument, "#{desc.inspect} does not describe a module!"
-        end
-
-        [mod_name, initial_constants]
-      end
-
-      constant_watch_stack_mutex.synchronize do
-        constant_watch_stack.concat watch_frames
-      end
+      watch_frames = constant_watch_stack.add_modules(descs)
 
       aborting = true
       begin
         yield # Now yield to the code that is to define new constants.
         aborting = false
       ensure
-        # Find the new constants.
-        new_constants = watch_frames.collect do |mod_name, prior_constants|
-          # Module still doesn't exist? Treat it as if it has no constants.
-          next [] unless qualified_const_defined?(mod_name)
-
-          mod = Inflector.constantize(mod_name)
-          next [] unless mod.is_a? Module
-          new_constants = mod.local_constant_names - prior_constants
-
-          # Make sure no other frames takes credit for these constants.
-          constant_watch_stack_mutex.synchronize do
-            constant_watch_stack.each do |frame_name, constants|
-              constants.concat new_constants if frame_name == mod_name
-            end
-          end
-
-          new_constants.collect do |suffix|
-            mod_name == "Object" ? suffix : "#{mod_name}::#{suffix}"
-          end
-        end.flatten
+        new_constants = constant_watch_stack.new_constants_for(watch_frames)
 
         log "New constants: #{new_constants * ', '}"
+        return new_constants unless aborting
 
-        if aborting
-          log "Error during loading, removing partially loaded constants "
-          new_constants.each { |name| remove_constant name }
-          new_constants.clear
-        end
+        log "Error during loading, removing partially loaded constants "
+        new_constants.each {|c| remove_constant(c) }.clear
       end
 
-      return new_constants
+      return []
     ensure
       # Remove the stack frames that we added.
-      if defined?(watch_frames) && ! watch_frames.blank?
-        frame_ids = watch_frames.collect { |frame| frame.object_id }
-        constant_watch_stack_mutex.synchronize do
-          constant_watch_stack.delete_if do |watch_frame|
-            frame_ids.include? watch_frame.object_id
-          end
-        end
-      end
+      watch_frames.each {|f| constant_watch_stack.delete(f) } if watch_frames.present?
     end
 
     class LoadingModule #:nodoc:
@@ -595,11 +544,11 @@ module ActiveSupport #:nodoc:
     # A module, class, symbol, or string may be provided.
     def to_constant_name(desc) #:nodoc:
       name = case desc
-        when String then desc.starts_with?('::') ? desc[2..-1] : desc
+        when String then desc.sub(/^::/, '')
         when Symbol then desc.to_s
         when Module
-          raise ArgumentError, "Anonymous modules have no name to be referenced by" if desc.name.blank?
-          desc.name
+          desc.name.presence ||
+            raise(ArgumentError, "Anonymous modules have no name to be referenced by")
         else raise TypeError, "Not a valid constant descriptor: #{desc.inspect}"
       end
     end
@@ -607,16 +556,13 @@ module ActiveSupport #:nodoc:
     def remove_constant(const) #:nodoc:
       return false unless qualified_const_defined? const
 
-      const = $1 if /\A::(.*)\Z/ =~ const.to_s
-      names = const.to_s.split('::')
-      if names.size == 1 # It's under Object
-        parent = Object
-      else
-        parent = Inflector.constantize(names[0..-2] * '::')
-      end
+      # Normalize ::Foo, Foo, Object::Foo, and ::Object::Foo to Object::Foo
+      names = const.to_s.sub(/^::(Object)?/, 'Object::').split("::")
+      to_remove = names.pop
+      parent = Inflector.constantize(names * '::')
 
       log "removing constant #{const}"
-      parent.instance_eval { remove_const names.last }
+      parent.instance_eval { remove_const to_remove }
       return true
     end
 
diff --git a/activesupport/lib/active_support/json/backends/yajl.rb b/activesupport/lib/active_support/json/backends/yajl.rb
new file mode 100644
index 0000000000..d76f8b03e4
--- /dev/null
+++ b/activesupport/lib/active_support/json/backends/yajl.rb
@@ -0,0 +1,40 @@
+require 'yajl-ruby' unless defined?(Yajl)
+
+module ActiveSupport
+  module JSON
+    module Backends
+      module Yajl
+        ParseError = ::Yajl::ParseError
+        extend self
+
+        # Parses a JSON string or IO and convert it into an object
+        def decode(json)
+          data = ::Yajl::Parser.new.parse(json)
+          if ActiveSupport.parse_json_times
+            convert_dates_from(data)
+          else
+            data
+          end
+        end
+
+      private
+        def convert_dates_from(data)
+          case data
+          when nil
+            nil
+          when DATE_REGEX
+            DateTime.parse(data)
+          when Array
+            data.map! { |d| convert_dates_from(d) }
+          when Hash
+            data.each do |key, value|
+              data[key] = convert_dates_from(value)
+            end
+          else
+            data
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/activesupport/lib/active_support/json/decoding.rb b/activesupport/lib/active_support/json/decoding.rb
index a5908365af..e357b6837a 100644
--- a/activesupport/lib/active_support/json/decoding.rb
+++ b/activesupport/lib/active_support/json/decoding.rb
@@ -6,12 +6,15 @@ module ActiveSupport
   mattr_accessor :parse_json_times
 
   module JSON
+    # Listed in order of preference.
+    DECODERS = %w(Yajl JSONGem Yaml)
+
     class << self
       attr_reader :parse_error
       delegate :decode, :to => :backend
 
       def backend
-        self.backend = "Yaml" unless defined?(@backend)
+        set_default_backend unless defined?(@backend)
         @backend
       end
 
@@ -31,6 +34,18 @@ module ActiveSupport
       ensure
         self.backend = old_backend
       end
+
+      def set_default_backend
+        DECODERS.find do |name|
+          begin
+            self.backend = name
+            true
+          rescue LoadError
+            # Try next decoder.
+            false
+          end
+        end
+      end
     end
   end
 end
diff --git a/activesupport/lib/active_support/test_case.rb b/activesupport/lib/active_support/test_case.rb
index 1646891e00..ab30984d62 100644
--- a/activesupport/lib/active_support/test_case.rb
+++ b/activesupport/lib/active_support/test_case.rb
@@ -21,12 +21,6 @@ module ActiveSupport
       alias_method :method_name, :name if method_defined? :name
       alias_method :method_name, :__name__ if method_defined? :__name__
     else
-      # TODO: Figure out how to get the Rails::BacktraceFilter into minitest/unit
-      if defined?(Rails) && ENV['BACKTRACE'].nil?
-        require 'rails/backtrace_cleaner'
-        Test::Unit::Util::BacktraceFilter.module_eval { include Rails::BacktraceFilterForTestUnit }
-      end
-
       Assertion = Test::Unit::AssertionFailedError
 
       require 'active_support/testing/default'
diff --git a/activesupport/lib/active_support/version.rb b/activesupport/lib/active_support/version.rb
index b92e469a08..6c6187be29 100644
--- a/activesupport/lib/active_support/version.rb
+++ b/activesupport/lib/active_support/version.rb
@@ -2,7 +2,7 @@ module ActiveSupport
   module VERSION #:nodoc:
     MAJOR = 3
     MINOR = 0
-    TINY  = "0.beta"
+    TINY  = "0.beta1"
 
     STRING = [MAJOR, MINOR, TINY].join('.')
   end
diff --git a/activesupport/lib/active_support/whiny_nil.rb b/activesupport/lib/active_support/whiny_nil.rb
index 4f6ff7d3b5..11b05efac1 100644
--- a/activesupport/lib/active_support/whiny_nil.rb
+++ b/activesupport/lib/active_support/whiny_nil.rb
@@ -11,7 +11,7 @@
 # classes in NilClass::WHINERS the error message suggests which could be the
 # actual intended class:
 #
-#   $ script/runner nil.destroy 
+#   $ rails runner nil.destroy
 #   ...
 #   You might have expected an instance of ActiveRecord::Base.
 #   ...