merge forward to current rails/master

19 files changed, 275 insertions, 65 deletions

diff --git a/activesupport/lib/active_support.rb b/activesupport/lib/active_support.rb
index de50aafe16..1df911a3f2 100644
--- a/activesupport/lib/active_support.rb
+++ b/activesupport/lib/active_support.rb
@@ -43,6 +43,7 @@ require 'active_support/ordered_hash'
 require 'active_support/ordered_options'
 require 'active_support/option_merger'
 
+require 'active_support/memoizable'
 require 'active_support/string_inquirer'
 
 require 'active_support/values/time_zone'
diff --git a/activesupport/lib/active_support/cache.rb b/activesupport/lib/active_support/cache.rb
index 2f1143e610..3e3dc18263 100644
--- a/activesupport/lib/active_support/cache.rb
+++ b/activesupport/lib/active_support/cache.rb
@@ -19,19 +19,19 @@ module ActiveSupport
 
     def self.expand_cache_key(key, namespace = nil)
       expanded_cache_key = namespace ? "#{namespace}/" : ""
-      
+
       if ENV["RAILS_CACHE_ID"] || ENV["RAILS_APP_VERSION"]
         expanded_cache_key << "#{ENV["RAILS_CACHE_ID"] || ENV["RAILS_APP_VERSION"]}/" 
       end
 
       expanded_cache_key << case
-      when key.respond_to?(:cache_key)
-        key.cache_key
-      when key.is_a?(Array)
-        key.collect { |element| expand_cache_key(element) }.to_param
-      when key.respond_to?(:to_param)
-        key.to_param
-      end
+        when key.respond_to?(:cache_key)
+          key.cache_key
+        when key.is_a?(Array)
+          key.collect { |element| expand_cache_key(element) }.to_param
+        when key
+          key.to_param
+        end.to_s
 
       expanded_cache_key
     end
diff --git a/activesupport/lib/active_support/core_ext/array/conversions.rb b/activesupport/lib/active_support/core_ext/array/conversions.rb
index 59dc96754f..e67b719ddb 100644
--- a/activesupport/lib/active_support/core_ext/array/conversions.rb
+++ b/activesupport/lib/active_support/core_ext/array/conversions.rb
@@ -30,7 +30,7 @@ module ActiveSupport #:nodoc:
         # Calls <tt>to_param</tt> on all its elements and joins the result with
         # slashes. This is used by <tt>url_for</tt> in Action Pack. 
         def to_param
-          map(&:to_param).join '/'
+          collect { |e| e.to_param }.join '/'
         end
 
         # Converts an array into a string suitable for use as a URL query string,
@@ -38,7 +38,8 @@ module ActiveSupport #:nodoc:
         #
         #   ['Rails', 'coding'].to_query('hobbies') # => "hobbies%5B%5D=Rails&hobbies%5B%5D=coding"
         def to_query(key)
-          collect { |value| value.to_query("#{key}[]") } * '&'
+          prefix = "#{key}[]"
+          collect { |value| value.to_query(prefix) }.join '&'
         end
 
         def self.included(base) #:nodoc:
diff --git a/activesupport/lib/active_support/core_ext/array/grouping.rb b/activesupport/lib/active_support/core_ext/array/grouping.rb
index 767acc4e07..df37afb053 100644
--- a/activesupport/lib/active_support/core_ext/array/grouping.rb
+++ b/activesupport/lib/active_support/core_ext/array/grouping.rb
@@ -4,8 +4,8 @@ module ActiveSupport #:nodoc:
   module CoreExtensions #:nodoc:
     module Array #:nodoc:
       module Grouping
-        # Iterates over the array in groups of size +number+, padding any remaining 
-        # slots with +fill_with+ unless it is +false+.
+        # Splits or iterates over the array in groups of size +number+,
+        # padding any remaining slots with +fill_with+ unless it is +false+.
         # 
         #   %w(1 2 3 4 5 6 7).in_groups_of(3) {|g| p g}
         #   ["1", "2", "3"]
@@ -39,6 +39,49 @@ module ActiveSupport #:nodoc:
           end
         end
 
+        # Splits or iterates over the array in +number+ of groups, padding any
+        # remaining slots with +fill_with+ unless it is +false+.
+        #
+        #   %w(1 2 3 4 5 6 7 8 9 10).in_groups(3) {|g| p g}
+        #   ["1", "2", "3", "4"]
+        #   ["5", "6", "7", nil]
+        #   ["8", "9", "10", nil]
+        #
+        #   %w(1 2 3 4 5 6 7).in_groups(3, '&nbsp;') {|g| p g}
+        #   ["1", "2", "3"]
+        #   ["4", "5", "&nbsp;"]
+        #   ["6", "7", "&nbsp;"]
+        #
+        #   %w(1 2 3 4 5 6 7).in_groups(3, false) {|g| p g}
+        #   ["1", "2", "3"]
+        #   ["4", "5"]
+        #   ["6", "7"]
+        def in_groups(number, fill_with = nil)
+          # size / number gives minor group size;
+          # size % number gives how many objects need extra accomodation;
+          # each group hold either division or division + 1 items.
+          division = size / number
+          modulo = size % number
+
+          # create a new array avoiding dup
+          groups = []
+          start = 0
+
+          number.times do |index|
+            length = division + (modulo > 0 && modulo > index ? 1 : 0)
+            padding = fill_with != false &&
+              modulo > 0 && length == division ? 1 : 0
+            groups << slice(start, length).concat([fill_with] * padding)
+            start += length
+          end
+
+          if block_given?
+            groups.each{|g| yield(g) }
+          else
+            groups
+          end
+        end
+
         # Divides the array into one or more subarrays based on a delimiting +value+
         # or the result of an optional block.
         #
diff --git a/activesupport/lib/active_support/core_ext/enumerable.rb b/activesupport/lib/active_support/core_ext/enumerable.rb
index 9647797ec2..e451e9933a 100644
--- a/activesupport/lib/active_support/core_ext/enumerable.rb
+++ b/activesupport/lib/active_support/core_ext/enumerable.rb
@@ -79,7 +79,9 @@ module Enumerable
   end
   
   # Returns true if the collection has more than 1 element. Functionally equivalent to collection.size > 1.
-  def many?
+  # Works with a block too ala any?, so people.many? { |p| p.age > 26 } # => returns true if more than 1 person is over 26.
+  def many?(&block)
+    size = block_given? ? select(&block).size : self.size
     size > 1
   end
 end
diff --git a/activesupport/lib/active_support/core_ext/module/introspection.rb b/activesupport/lib/active_support/core_ext/module/introspection.rb
index 40bbebb7c4..45f3e4bf5c 100644
--- a/activesupport/lib/active_support/core_ext/module/introspection.rb
+++ b/activesupport/lib/active_support/core_ext/module/introspection.rb
@@ -1,4 +1,14 @@
 class Module
+  # Returns the name of the module containing this one.
+  #
+  #   p M::N.parent_name # => "M"
+  def parent_name
+    unless defined? @parent_name
+      @parent_name = name =~ /::[^:]+\Z/ ? $`.freeze : nil
+    end
+    @parent_name
+  end
+
   # Returns the module which contains this one according to its name.
   #
   #   module M
@@ -16,8 +26,7 @@ class Module
   #   p Module.new.parent # => Object
   #
   def parent
-    parent_name = name.split('::')[0..-2] * '::'
-    parent_name.empty? ? Object : parent_name.constantize
+    parent_name ? parent_name.constantize : Object
   end
 
   # Returns all the parents of this module according to its name, ordered from
@@ -35,10 +44,12 @@ class Module
   #
   def parents
     parents = []
-    parts = name.split('::')[0..-2]
-    until parts.empty?
-      parents << (parts * '::').constantize
-      parts.pop
+    if parent_name
+      parts = parent_name.split('::')
+      until parts.empty?
+        parents << (parts * '::').constantize
+        parts.pop
+      end
     end
     parents << Object unless parents.include? Object
     parents
@@ -70,6 +81,6 @@ class Module
   # Returns the names of the constants defined locally rather than the
   # constants themselves. See <tt>local_constants</tt>.
   def local_constant_names
-    local_constants.map(&:to_s)
+    local_constants.map { |c| c.to_s }
   end
 end
diff --git a/activesupport/lib/active_support/core_ext/module/model_naming.rb b/activesupport/lib/active_support/core_ext/module/model_naming.rb
index 26e76ab556..5518f5417b 100644
--- a/activesupport/lib/active_support/core_ext/module/model_naming.rb
+++ b/activesupport/lib/active_support/core_ext/module/model_naming.rb
@@ -1,12 +1,13 @@
 module ActiveSupport
   class ModelName < String
-    attr_reader :singular, :plural, :partial_path
+    attr_reader :singular, :plural, :cache_key, :partial_path
 
     def initialize(name)
       super
       @singular = underscore.tr('/', '_').freeze
       @plural = @singular.pluralize.freeze
-      @partial_path = "#{tableize}/#{demodulize.underscore}".freeze
+      @cache_key = tableize.freeze
+      @partial_path = "#{@cache_key}/#{demodulize.underscore}".freeze
     end
   end
 
diff --git a/activesupport/lib/active_support/core_ext/object/instance_variables.rb b/activesupport/lib/active_support/core_ext/object/instance_variables.rb
index 9f1d4ed2aa..4ecaab3bbb 100644
--- a/activesupport/lib/active_support/core_ext/object/instance_variables.rb
+++ b/activesupport/lib/active_support/core_ext/object/instance_variables.rb
@@ -35,7 +35,7 @@ class Object
   #   C.new(0, 1).instance_variable_names # => ["@y", "@x"]
   if RUBY_VERSION >= '1.9'
     def instance_variable_names
-      instance_variables.map(&:to_s)
+      instance_variables.map { |var| var.to_s }
     end
   else
     alias_method :instance_variable_names, :instance_variables
diff --git a/activesupport/lib/active_support/core_ext/test.rb b/activesupport/lib/active_support/core_ext/test.rb
deleted file mode 100644
index c0b19bdc58..0000000000
--- a/activesupport/lib/active_support/core_ext/test.rb
+++ /dev/null
@@ -1 +0,0 @@
-require 'active_support/core_ext/test/unit/assertions'
diff --git a/activesupport/lib/active_support/dependencies.rb b/activesupport/lib/active_support/dependencies.rb
index 7a8c4d0326..2f3fa72bb4 100644
--- a/activesupport/lib/active_support/dependencies.rb
+++ b/activesupport/lib/active_support/dependencies.rb
@@ -299,7 +299,7 @@ module ActiveSupport #:nodoc:
 
     # Will the provided constant descriptor be unloaded?
     def will_unload?(const_desc)
-      autoloaded?(desc) ||
+      autoloaded?(const_desc) ||
         explicitly_unloadable_constants.include?(to_constant_name(const_desc))
     end
 
@@ -387,7 +387,7 @@ module ActiveSupport #:nodoc:
     ensure
       # Remove the stack frames that we added.
       if defined?(watch_frames) && ! watch_frames.blank?
-        frame_ids = watch_frames.collect(&:object_id)
+        frame_ids = watch_frames.collect { |frame| frame.object_id }
         constant_watch_stack.delete_if do |watch_frame|
           frame_ids.include? watch_frame.object_id
         end
@@ -437,7 +437,7 @@ module ActiveSupport #:nodoc:
     protected
       def log_call(*args)
         if defined?(RAILS_DEFAULT_LOGGER) && RAILS_DEFAULT_LOGGER && log_activity
-          arg_str = args.collect(&:inspect) * ', '
+          arg_str = args.collect { |arg| arg.inspect } * ', '
           /in `([a-z_\?\!]+)'/ =~ caller(1).first
           selector = $1 || '<unknown>'
           log "called #{selector}(#{arg_str})"
diff --git a/activesupport/lib/active_support/inflector.rb b/activesupport/lib/active_support/inflector.rb
index 47bd6e1767..6651569d33 100644
--- a/activesupport/lib/active_support/inflector.rb
+++ b/activesupport/lib/active_support/inflector.rb
@@ -30,10 +30,10 @@ module ActiveSupport
     class Inflections
       include Singleton
 
-      attr_reader :plurals, :singulars, :uncountables
+      attr_reader :plurals, :singulars, :uncountables, :humans
 
       def initialize
-        @plurals, @singulars, @uncountables = [], [], []
+        @plurals, @singulars, @uncountables, @humans = [], [], [], []
       end
 
       # Specifies a new pluralization rule and its replacement. The rule can either be a string or a regular expression.
@@ -76,9 +76,20 @@ module ActiveSupport
         (@uncountables << words).flatten!
       end
 
+      # Specifies a humanized form of a string by a regular expression rule or by a string mapping.
+      # When using a regular expression based replacement, the normal humanize formatting is called after the replacement.
+      # When a string is used, the human form should be specified as desired (example: 'The name', not 'the_name')
+      #
+      # Examples:
+      #   human /_cnt$/i, '\1_count'
+      #   human "legacy_col_person_name", "Name"
+      def human(rule, replacement)
+        @humans.insert(0, [rule, replacement])
+      end
+
       # Clears the loaded inflections within a given scope (default is <tt>:all</tt>).
       # Give the scope as a symbol of the inflection type, the options are: <tt>:plurals</tt>,
-      # <tt>:singulars</tt>, <tt>:uncountables</tt>.
+      # <tt>:singulars</tt>, <tt>:uncountables</tt>, <tt>:humans</tt>.
       #
       # Examples:
       #   clear :all
@@ -209,7 +220,10 @@ module ActiveSupport
     #   "employee_salary" # => "Employee salary"
     #   "author_id"       # => "Author"
     def humanize(lower_case_and_underscored_word)
-      lower_case_and_underscored_word.to_s.gsub(/_id$/, "").gsub(/_/, " ").capitalize
+      result = lower_case_and_underscored_word.to_s.dup
+
+      inflections.humans.each { |(rule, replacement)| break if result.gsub!(rule, replacement) }
+      result.gsub(/_id$/, "").gsub(/_/, " ").capitalize
     end
 
     # Removes the module part from the expression in the string.
@@ -307,4 +321,9 @@ module ActiveSupport
   end
 end
 
+# in case active_support/inflector is required without the rest of active_support
 require 'active_support/inflections'
+require 'active_support/core_ext/string/inflections'
+unless String.included_modules.include?(ActiveSupport::CoreExtensions::String::Inflections)
+  String.send :include, ActiveSupport::CoreExtensions::String::Inflections
+end
\ No newline at end of file
diff --git a/activesupport/lib/active_support/json/encoders/date_time.rb b/activesupport/lib/active_support/json/encoders/date_time.rb
index d41c3e9786..a4a5efbfb1 100644
--- a/activesupport/lib/active_support/json/encoders/date_time.rb
+++ b/activesupport/lib/active_support/json/encoders/date_time.rb
@@ -8,7 +8,7 @@ class DateTime
     if ActiveSupport.use_standard_json_time_format
       xmlschema.inspect
     else
-      %("#{strftime("%Y/%m/%d %H:%M:%S %z")}")
+      strftime('"%Y/%m/%d %H:%M:%S %z"')
     end
   end
 end
diff --git a/activesupport/lib/active_support/memoizable.rb b/activesupport/lib/active_support/memoizable.rb
new file mode 100644
index 0000000000..d06250171a
--- /dev/null
+++ b/activesupport/lib/active_support/memoizable.rb
@@ -0,0 +1,35 @@
+module ActiveSupport
+  module Memoizable
+    def self.included(base) #:nodoc:
+      base.extend(ClassMethods)
+    end
+
+    module ClassMethods
+      def memoize(symbol)
+        original_method = "_unmemoized_#{symbol}"
+        memoized_ivar = "@_memoized_#{symbol}"
+        raise "Already memoized #{symbol}" if instance_methods.map(&:to_s).include?(original_method)
+
+        alias_method original_method, symbol
+        class_eval <<-EOS, __FILE__, __LINE__
+          def #{symbol}
+            if defined? #{memoized_ivar}
+              #{memoized_ivar}
+            else
+              #{memoized_ivar} = #{original_method}
+            end
+          end
+        EOS
+      end
+    end
+
+    def freeze
+      methods.each do |method|
+        if m = method.to_s.match(/\A_unmemoized_(.*)/)
+          send(m[1]).freeze
+        end
+      end
+      super
+    end
+  end
+end
diff --git a/activesupport/lib/active_support/test_case.rb b/activesupport/lib/active_support/test_case.rb
index 2fd02d5313..0f531b0c79 100644
--- a/activesupport/lib/active_support/test_case.rb
+++ b/activesupport/lib/active_support/test_case.rb
@@ -1,11 +1,7 @@
 require 'test/unit/testcase'
-require 'active_support/testing/setup_and_teardown'
 require 'active_support/testing/default'
+require 'active_support/testing/core_ext/test'
 
-# TODO: move to core_ext
-class Test::Unit::TestCase #:nodoc:
-  include ActiveSupport::Testing::SetupAndTeardown
-end
 
 module ActiveSupport
   class TestCase < Test::Unit::TestCase
diff --git a/activesupport/lib/active_support/testing/core_ext/test.rb b/activesupport/lib/active_support/testing/core_ext/test.rb
new file mode 100644
index 0000000000..d3f38f0bc7
--- /dev/null
+++ b/activesupport/lib/active_support/testing/core_ext/test.rb
@@ -0,0 +1,6 @@
+require 'active_support/testing/core_ext/test/unit/assertions'
+require 'active_support/testing/setup_and_teardown'
+
+class Test::Unit::TestCase #:nodoc:
+  include ActiveSupport::Testing::SetupAndTeardown
+end
\ No newline at end of file
diff --git a/activesupport/lib/active_support/core_ext/test/unit/assertions.rb b/activesupport/lib/active_support/testing/core_ext/test/unit/assertions.rb
index 77fe325fb4..70a44eab8c 100644
--- a/activesupport/lib/active_support/core_ext/test/unit/assertions.rb
+++ b/activesupport/lib/active_support/testing/core_ext/test/unit/assertions.rb
@@ -1,9 +1,10 @@
-module Test 
-  module Unit 
+require 'test/unit/assertions'
+module Test
+  module Unit
     #--
     # FIXME: no Proc#binding in Ruby 2, must change this API
     #++
-    module Assertions 
+    module Assertions
       # Test numeric difference between the return value of an expression as a result of what is evaluated
       # in the yielded block.
       #
diff --git a/activesupport/lib/active_support/testing/performance.rb b/activesupport/lib/active_support/testing/performance.rb
index 24936029a2..5f2027eb3b 100644
--- a/activesupport/lib/active_support/testing/performance.rb
+++ b/activesupport/lib/active_support/testing/performance.rb
@@ -12,13 +12,13 @@ module ActiveSupport
         if benchmark = ARGV.include?('--benchmark')  # HAX for rake test
           { :benchmark => true,
             :runs => 10,
-            :metrics => [:process_time, :memory, :objects],
+            :metrics => [:process_time, :memory, :objects, :gc_runs, :gc_time],
             :output => 'tmp/performance' }
         else
           { :benchmark => false,
             :runs => 1,
             :min_percent => 0.02,
-            :metrics => [:wall_time, :memory, :objects],
+            :metrics => [:process_time, :memory, :objects],
             :formats => [:flat, :graph_html, :call_tree],
             :output => 'tmp/performance' }
         end
@@ -44,7 +44,7 @@ module ActiveSupport
             run_profile(klass.new)
             result.add_run
           else
-            $stderr.puts "Skipping unknown metric #{metric_name.inspect}. Expected :process_time, :wall_time, :cpu_time, :memory, or :objects."
+            $stderr.puts '%20s: unsupported' % metric_name.to_s
           end
         end
 
@@ -72,9 +72,13 @@ module ActiveSupport
 
       protected
         def run_warmup
+          5.times { GC.start }
+
           time = Metrics::Time.new
           run_test(time, :benchmark)
           puts "%s (%s warmup)" % [full_test_name, time.format(time.total)]
+
+          5.times { GC.start }
         end
 
         def run_profile(metric)
@@ -95,8 +99,13 @@ module ActiveSupport
 
         def report
           rate = @total / profile_options[:runs]
-          '%20s: %s/run' % [@metric.name, @metric.format(rate)]
+          '%20s: %s' % [@metric.name, @metric.format(rate)]
         end
+
+        protected
+          def output_filename
+            "#{profile_options[:output]}/#{full_test_name}_#{@metric.name}"
+          end
       end
 
       class Benchmarker < Performer
@@ -107,9 +116,9 @@ module ActiveSupport
 
         def record
           avg = @metric.total / profile_options[:runs].to_i
-          data = [full_test_name, @metric.name, avg, Time.now.utc.xmlschema] * ','
+          now = Time.now.utc.xmlschema
           with_output_file do |file|
-            file.puts "#{data},#{environment}"
+            file.puts "#{avg},#{now},#{environment}"
           end
         end
 
@@ -134,10 +143,10 @@ module ActiveSupport
         end
 
         protected
-          HEADER = 'test,metric,measurement,created_at,app,rails,ruby,platform'
+          HEADER = 'measurement,created_at,app,rails,ruby,platform'
 
           def with_output_file
-            fname = "#{profile_options[:output]}/benchmarks.csv"
+            fname = output_filename
 
             if new = !File.exist?(fname)
               FileUtils.mkdir_p(File.dirname(fname))
@@ -148,6 +157,10 @@ module ActiveSupport
               yield file
             end
           end
+
+          def output_filename
+            "#{super}.csv"
+          end
       end
 
       class Profiler < Performer
@@ -183,7 +196,7 @@ module ActiveSupport
                 else printer_class.name.sub(/Printer$/, '').underscore
               end
 
-            "#{profile_options[:output]}/#{full_test_name}_#{@metric.name}_#{suffix}"
+            "#{super()}_#{suffix}"
           end
       end
 
@@ -210,6 +223,10 @@ module ActiveSupport
             self.class::Mode
           end
 
+          def measure
+            0
+          end
+
           def benchmark
             with_gc_stats do
               before = measure
@@ -271,7 +288,7 @@ module ActiveSupport
         end
 
         class CpuTime < Time
-          Mode = RubyProf::CPU_TIME
+          Mode = RubyProf::CPU_TIME if RubyProf.const_defined?(:CPU_TIME)
 
           def initialize(*args)
             # FIXME: yeah my CPU is 2.33 GHz
@@ -285,16 +302,27 @@ module ActiveSupport
         end
 
         class Memory < Base
-          Mode = RubyProf::MEMORY
+          Mode = RubyProf::MEMORY if RubyProf.const_defined?(:MEMORY)
 
+          # ruby-prof wrapper
           if RubyProf.respond_to?(:measure_memory)
             def measure
               RubyProf.measure_memory / 1024.0
             end
+
+          # Ruby 1.8 + adymo patch
           elsif GC.respond_to?(:allocated_size)
             def measure
               GC.allocated_size / 1024.0
             end
+
+          # Ruby 1.8 + lloyd patch
+          elsif GC.respond_to?(:heap_info)
+            def measure
+              GC.heap_info['heap_current_memory'] / 1024.0
+            end
+
+          # Ruby 1.9 unpatched
           elsif GC.respond_to?(:malloc_allocated_size)
             def measure
               GC.malloc_allocated_size / 1024.0
@@ -307,7 +335,7 @@ module ActiveSupport
         end
 
         class Objects < Base
-          Mode = RubyProf::ALLOCATIONS
+          Mode = RubyProf::ALLOCATIONS if RubyProf.const_defined?(:ALLOCATIONS)
 
           if RubyProf.respond_to?(:measure_allocations)
             def measure
@@ -323,6 +351,46 @@ module ActiveSupport
             measurement.to_i.to_s
           end
         end
+
+        class GcRuns < Base
+          Mode = RubyProf::GC_RUNS if RubyProf.const_defined?(:GC_RUNS)
+
+          if RubyProf.respond_to?(:measure_gc_runs)
+            def measure
+              RubyProf.measure_gc_runs
+            end
+          elsif GC.respond_to?(:collections)
+            def measure
+              GC.collections
+            end
+          elsif GC.respond_to?(:heap_info)
+            def measure
+              GC.heap_info['num_gc_passes']
+            end
+          end
+
+          def format(measurement)
+            measurement.to_i.to_s
+          end
+        end
+
+        class GcTime < Base
+          Mode = RubyProf::GC_TIME if RubyProf.const_defined?(:GC_TIME)
+
+          if RubyProf.respond_to?(:measure_gc_time)
+            def measure
+              RubyProf.measure_gc_time
+            end
+          elsif GC.respond_to?(:time)
+            def measure
+              GC.time
+            end
+          end
+
+          def format(measurement)
+            '%d ms' % (measurement / 1000)
+          end
+        end
       end
     end
   end
diff --git a/activesupport/lib/active_support/time_with_zone.rb b/activesupport/lib/active_support/time_with_zone.rb
index bfc5b16039..e85bfe9b2e 100644
--- a/activesupport/lib/active_support/time_with_zone.rb
+++ b/activesupport/lib/active_support/time_with_zone.rb
@@ -159,19 +159,24 @@ module ActiveSupport
       utc == other
     end
     
-    # If wrapped +time+ is a DateTime, use DateTime#since instead of <tt>+</tt>.
-    # Otherwise, just pass on to +method_missing+.
     def +(other)
-      result = utc.acts_like?(:date) ? utc.since(other) : utc + other rescue utc.since(other)
-      result.in_time_zone(time_zone)
+      # If we're adding a Duration of variable length (i.e., years, months, days), move forward from #time,
+      # otherwise move forward from #utc, for accuracy when moving across DST boundaries
+      if duration_of_variable_length?(other)
+        method_missing(:+, other)
+      else
+        result = utc.acts_like?(:date) ? utc.since(other) : utc + other rescue utc.since(other)
+        result.in_time_zone(time_zone)
+      end
     end
-    
-    # If a time-like object is passed in, compare it with +utc+.
-    # Else if wrapped +time+ is a DateTime, use DateTime#ago instead of DateTime#-.
-    # Otherwise, just pass on to +method_missing+.
+
     def -(other)
+      # If we're subtracting a Duration of variable length (i.e., years, months, days), move backwards from #time,
+      # otherwise move backwards #utc, for accuracy when moving across DST boundaries
       if other.acts_like?(:time)
         utc - other
+      elsif duration_of_variable_length?(other)
+        method_missing(:-, other)
       else
         result = utc.acts_like?(:date) ? utc.ago(other) : utc - other rescue utc.ago(other)
         result.in_time_zone(time_zone)
@@ -179,15 +184,27 @@ module ActiveSupport
     end
     
     def since(other)
-      utc.since(other).in_time_zone(time_zone)
+      # If we're adding a Duration of variable length (i.e., years, months, days), move forward from #time,
+      # otherwise move forward from #utc, for accuracy when moving across DST boundaries
+      if duration_of_variable_length?(other)
+        method_missing(:since, other)
+      else
+        utc.since(other).in_time_zone(time_zone)
+      end
     end
     
     def ago(other)
-      utc.ago(other).in_time_zone(time_zone)
+      since(-other)
     end
-    
+
     def advance(options)
-      utc.advance(options).in_time_zone(time_zone)
+      # If we're advancing a value of variable length (i.e., years, weeks, months, days), advance from #time,
+      # otherwise advance from #utc, for accuracy when moving across DST boundaries
+      if options.detect {|k,v| [:years, :weeks, :months, :days].include? k}
+        method_missing(:advance, options)
+      else
+        utc.advance(options).in_time_zone(time_zone)
+      end
     end
     
     %w(year mon month day mday hour min sec).each do |method_name|
@@ -246,7 +263,7 @@ module ActiveSupport
     end
     
     def marshal_load(variables)
-      initialize(variables[0], ::Time.send!(:get_zone, variables[1]), variables[2])
+      initialize(variables[0].utc, ::Time.send!(:get_zone, variables[1]), variables[2].utc)
     end
 
     # Ensure proxy class responds to all methods that underlying time instance responds to.
@@ -279,5 +296,9 @@ module ActiveSupport
       def transfer_time_values_to_utc_constructor(time)
         ::Time.utc_time(time.year, time.month, time.day, time.hour, time.min, time.sec, time.respond_to?(:usec) ? time.usec : 0)
       end
+      
+      def duration_of_variable_length?(obj)
+        ActiveSupport::Duration === obj && obj.parts.flatten.detect {|p| [:years, :months, :days].include? p }
+      end
   end
 end
diff --git a/activesupport/lib/active_support/values/time_zone.rb b/activesupport/lib/active_support/values/time_zone.rb
index 5b2d42aa3c..788d40bfa8 100644
--- a/activesupport/lib/active_support/values/time_zone.rb
+++ b/activesupport/lib/active_support/values/time_zone.rb
@@ -201,6 +201,12 @@ module ActiveSupport
       result
     end
 
+    # Compare #name and TZInfo identifier to a supplied regexp, returning true
+    # if a match is found.
+    def =~(re)
+      return true if name =~ re || MAPPING[name] =~ re
+    end
+
     # Returns a textual representation of this time zone.
     def to_s
       "(GMT#{formatted_offset}) #{name}"