Merge commit 'mainstream/master'

Conflicts:

	activerecord/lib/active_record/association_preload.rb

5 files changed, 152 insertions, 18 deletions

diff --git a/activesupport/lib/active_support.rb b/activesupport/lib/active_support.rb
index b30faff06d..0ff09067ec 100644
--- a/activesupport/lib/active_support.rb
+++ b/activesupport/lib/active_support.rb
@@ -56,6 +56,8 @@ require 'active_support/time_with_zone'
 
 require 'active_support/secure_random'
 
+require 'active_support/rescuable'
+
 I18n.load_path << File.dirname(__FILE__) + '/active_support/locale/en-US.yml'
 
 Inflector = ActiveSupport::Deprecation::DeprecatedConstantProxy.new('Inflector', 'ActiveSupport::Inflector')
diff --git a/activesupport/lib/active_support/core_ext/object/extending.rb b/activesupport/lib/active_support/core_ext/object/extending.rb
index 082e98a297..bbf6f8563b 100644
--- a/activesupport/lib/active_support/core_ext/object/extending.rb
+++ b/activesupport/lib/active_support/core_ext/object/extending.rb
@@ -3,22 +3,43 @@ class Object
     Class.remove_class(*subclasses_of(*superclasses))
   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 subclasses_of(*superclasses) #:nodoc:
-    subclasses = []
-
-    superclasses.each do |sup|
-      ObjectSpace.each_object(class << sup; self; end) do |k|
-        if k != sup && (k.name.blank? || eval("defined?(::#{k}) && ::#{k}.object_id == k.object_id"))
-          subclasses << k
+  begin
+    ObjectSpace.each_object(Class.new) {}
+
+    # 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:
+      subclasses = []
+
+      superclasses.each do |sup|
+        ObjectSpace.each_object(class << sup; self; end) do |k|
+          if k != sup && (k.name.blank? || eval("defined?(::#{k}) && ::#{k}.object_id == k.object_id"))
+            subclasses << k
+          end
         end
       end
+
+      subclasses
     end
+  rescue RuntimeError
+    # JRuby and any implementations which cannot handle the objectspace traversal
+    # above fall back to this implementation
+    def subclasses_of(*superclasses) #:nodoc:
+      subclasses = []
 
-    subclasses
+      superclasses.each do |sup|
+        ObjectSpace.each_object(Class) do |k|
+          if superclasses.any? { |superclass| k < superclass } &&
+            (k.name.blank? || eval("defined?(::#{k}) && ::#{k}.object_id == k.object_id"))
+            subclasses << k
+          end
+        end
+        subclasses.uniq!
+      end
+      subclasses
+    end
   end
 
   def extended_by #:nodoc:
diff --git a/activesupport/lib/active_support/rescuable.rb b/activesupport/lib/active_support/rescuable.rb
new file mode 100644
index 0000000000..f2bc12e832
--- /dev/null
+++ b/activesupport/lib/active_support/rescuable.rb
@@ -0,0 +1,108 @@
+module ActiveSupport
+  # Rescuable module adds support for easier exception handling.
+  module Rescuable
+    def self.included(base) # :nodoc:
+      base.class_inheritable_accessor :rescue_handlers
+      base.rescue_handlers = []
+
+      base.extend(ClassMethods)
+    end
+
+    module ClassMethods
+      # Rescue exceptions raised in controller actions.
+      #
+      # <tt>rescue_from</tt> receives a series of exception classes or class
+      # names, and a trailing <tt>:with</tt> option with the name of a method
+      # or a Proc object to be called to handle them. Alternatively a block can
+      # be given.
+      #
+      # Handlers that take one argument will be called with the exception, so
+      # that the exception can be inspected when dealing with it.
+      #
+      # Handlers are inherited. They are searched from right to left, from
+      # bottom to top, and up the hierarchy. The handler of the first class for
+      # which <tt>exception.is_a?(klass)</tt> holds true is the one invoked, if
+      # any.
+      #
+      #   class ApplicationController < ActionController::Base
+      #     rescue_from User::NotAuthorized, :with => :deny_access # self defined exception
+      #     rescue_from ActiveRecord::RecordInvalid, :with => :show_errors
+      #
+      #     rescue_from 'MyAppError::Base' do |exception|
+      #       render :xml => exception, :status => 500
+      #     end
+      #
+      #     protected
+      #       def deny_access
+      #         ...
+      #       end
+      #
+      #       def show_errors(exception)
+      #         exception.record.new_record? ? ...
+      #       end
+      #   end
+      def rescue_from(*klasses, &block)
+        options = klasses.extract_options!
+
+        unless options.has_key?(:with)
+          if block_given?
+            options[:with] = block
+          else
+            raise ArgumentError, "Need a handler. Supply an options hash that has a :with key as the last argument."
+          end
+        end
+
+        klasses.each do |klass|
+          key = if klass.is_a?(Class) && klass <= Exception
+            klass.name
+          elsif klass.is_a?(String)
+            klass
+          else
+            raise ArgumentError, "#{klass} is neither an Exception nor a String"
+          end
+
+          # put the new handler at the end because the list is read in reverse
+          rescue_handlers << [key, options[:with]]
+        end
+      end
+    end
+
+    # Tries to rescue the exception by looking up and calling a registered handler.
+    def rescue_with_handler(exception)
+      if handler = handler_for_rescue(exception)
+        handler.arity != 0 ? handler.call(exception) : handler.call
+        true # don't rely on the return value of the handler
+      end
+    end
+
+    def handler_for_rescue(exception)
+      # We go from right to left because pairs are pushed onto rescue_handlers
+      # as rescue_from declarations are found.
+      _, handler = Array(rescue_handlers).reverse.detect do |klass_name, handler|
+        # The purpose of allowing strings in rescue_from is to support the
+        # declaration of handler associations for exception classes whose
+        # definition is yet unknown.
+        #
+        # Since this loop needs the constants it would be inconsistent to
+        # assume they should exist at this point. An early raised exception
+        # could trigger some other handler and the array could include
+        # precisely a string whose corresponding constant has not yet been
+        # seen. This is why we are tolerant to unknown constants.
+        #
+        # Note that this tolerance only matters if the exception was given as
+        # a string, otherwise a NameError will be raised by the interpreter
+        # itself when rescue_from CONSTANT is executed.
+        klass = self.class.const_get(klass_name) rescue nil
+        klass ||= klass_name.constantize rescue nil
+        exception.is_a?(klass) if klass
+      end
+
+      case handler
+      when Symbol
+        method(handler)
+      when Proc
+        handler.bind(self)
+      end
+    end
+  end
+end
diff --git a/activesupport/lib/active_support/secure_random.rb b/activesupport/lib/active_support/secure_random.rb
index 688165f9a3..97971e8830 100644
--- a/activesupport/lib/active_support/secure_random.rb
+++ b/activesupport/lib/active_support/secure_random.rb
@@ -164,13 +164,13 @@ module ActiveSupport
           hex = n.to_s(16)
           hex = '0' + hex if (hex.length & 1) == 1
           bin = [hex].pack("H*")
-          mask = bin[0].ord
+          mask = bin[0]
           mask |= mask >> 1
           mask |= mask >> 2
           mask |= mask >> 4
           begin
             rnd = SecureRandom.random_bytes(bin.length)
-            rnd[0] = (rnd[0].ord & mask).chr
+            rnd[0] = rnd[0] & mask
           end until rnd < bin
           rnd.unpack("H*")[0].hex
         else
diff --git a/activesupport/lib/active_support/testing/core_ext/test/unit/assertions.rb b/activesupport/lib/active_support/testing/core_ext/test/unit/assertions.rb
index 63d1ba6507..e5853bf828 100644
--- a/activesupport/lib/active_support/testing/core_ext/test/unit/assertions.rb
+++ b/activesupport/lib/active_support/testing/core_ext/test/unit/assertions.rb
@@ -37,15 +37,18 @@ module Test
       #   end
       def assert_difference(expressions, difference = 1, message = nil, &block)
         expression_evaluations = Array(expressions).map do |expression|
-          lambda do
+          [expression, lambda do
             eval(expression, block.__send__(:binding))
-          end
+          end]
         end
 
-        original_values = expression_evaluations.inject([]) { |memo, expression| memo << expression.call }
+        original_values = expression_evaluations.inject([]) { |memo, expression| memo << expression[1].call }
         yield
         expression_evaluations.each_with_index do |expression, i|
-          assert_equal original_values[i] + difference, expression.call, message
+          full_message = ""
+          full_message << "#{message}.\n" if message
+          full_message << "<#{expression[0]}> was the expression that failed"
+          assert_equal original_values[i] + difference, expression[1].call, full_message
         end
       end