7 files changed, 28 insertions, 15 deletions
diff --git a/activemodel/lib/active_model/attribute_methods.rb b/activemodel/lib/active_model/attribute_methods.rb
index ea07c5c039..96be551264 100644
--- a/activemodel/lib/active_model/attribute_methods.rb
+++ b/activemodel/lib/active_model/attribute_methods.rb
@@ -353,14 +353,12 @@ module ActiveModel
           @attribute_method_matchers_cache ||= ThreadSafe::Cache.new(initial_capacity: 4)
         end
 
-        def attribute_method_matcher(method_name) #:nodoc:
+        def attribute_method_matchers_matching(method_name) #:nodoc:
           attribute_method_matchers_cache.compute_if_absent(method_name) do
             # Must try to match prefixes/suffixes first, or else the matcher with no prefix/suffix
             # will match every time.
             matchers = attribute_method_matchers.partition(&:plain?).reverse.flatten(1)
-            match = nil
-            matchers.detect { |method| match = method.match(method_name) }
-            match
+            matchers.map { |method| method.match(method_name) }.compact
           end
         end
 
@@ -469,8 +467,8 @@ module ActiveModel
       # Returns a struct representing the matching attribute method.
       # The struct's attributes are prefix, base and suffix.
       def match_attribute_method?(method_name)
-        match = self.class.send(:attribute_method_matcher, method_name)
-        match if match && attribute_method?(match.attr_name)
+        matches = self.class.send(:attribute_method_matchers_matching, method_name)
+        matches.detect { |match| attribute_method?(match.attr_name) }
       end
 
       def missing_attribute(attr_name, stack)
diff --git a/activemodel/lib/active_model/dirty.rb b/activemodel/lib/active_model/dirty.rb
index 4e389c8692..337b61c55c 100644
--- a/activemodel/lib/active_model/dirty.rb
+++ b/activemodel/lib/active_model/dirty.rb
@@ -13,7 +13,7 @@ module ActiveModel
   # * <tt>include ActiveModel::Dirty</tt> in your object.
   # * Call <tt>define_attribute_methods</tt> passing each method you want to
   #   track.
-  # * Call <tt>attr_name_will_change!</tt> before each change to the tracked
+  # * Call <tt>[attr_name]_will_change!</tt> before each change to the tracked
   #   attribute.
   # * Call <tt>changes_applied</tt> after the changes are persisted.
   # * Call <tt>clear_changes_information</tt> when you want to reset the changes
@@ -170,7 +170,7 @@ module ActiveModel
 
     # Handle <tt>*_changed?</tt> for +method_missing+.
     def attribute_changed?(attr, options = {}) #:nodoc:
-      result = changed_attributes.include?(attr)
+      result = changes_include?(attr)
       result &&= options[:to] == __send__(attr) if options.key?(:to)
       result &&= options[:from] == changed_attributes[attr] if options.key?(:from)
       result
@@ -188,6 +188,10 @@ module ActiveModel
 
     private
 
+      def changes_include?(attr_name)
+        attributes_changed_by_setter.include?(attr_name)
+      end
+
       # Removes current changes and makes them accessible through +previous_changes+.
       def changes_applied # :doc:
         @previously_changed = changes
diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 9105ef5dd6..55687cb3c7 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -283,9 +283,9 @@ module ActiveModel
     # ActiveModel::StrictValidationFailed instead of adding the error.
     # <tt>:strict</tt> option can also be set to any other exception.
     #
-    #   person.errors.add(:name, nil, strict: true)
+    #   person.errors.add(:name, :invalid, strict: true)
     #   # => ActiveModel::StrictValidationFailed: name is invalid
-    #   person.errors.add(:name, nil, strict: NameIsInvalid)
+    #   person.errors.add(:name, :invalid, strict: NameIsInvalid)
     #   # => NameIsInvalid: name is invalid
     #
     #   person.errors.messages # => {}
diff --git a/activemodel/lib/active_model/gem_version.rb b/activemodel/lib/active_model/gem_version.rb
index 932fe3e5a9..2403242ce6 100644
--- a/activemodel/lib/active_model/gem_version.rb
+++ b/activemodel/lib/active_model/gem_version.rb
@@ -5,10 +5,10 @@ module ActiveModel
   end
 
   module VERSION
-    MAJOR = 4
-    MINOR = 2
+    MAJOR = 5
+    MINOR = 0
     TINY  = 0
-    PRE   = "beta4"
+    PRE   = "alpha"
 
     STRING = [MAJOR, MINOR, TINY, PRE].compact.join(".")
   end
diff --git a/activemodel/lib/active_model/secure_password.rb b/activemodel/lib/active_model/secure_password.rb
index 8f2a069ba3..96e88f1b6c 100644
--- a/activemodel/lib/active_model/secure_password.rb
+++ b/activemodel/lib/active_model/secure_password.rb
@@ -99,7 +99,7 @@ module ActiveModel
       #   user.authenticate('notright')      # => false
       #   user.authenticate('mUc3m00RsqyRe') # => user
       def authenticate(unencrypted_password)
-        BCrypt::Password.new(password_digest) == unencrypted_password && self
+        BCrypt::Password.new(password_digest).is_password?(unencrypted_password) && self
       end
 
       attr_reader :password
diff --git a/activemodel/lib/active_model/validations.rb b/activemodel/lib/active_model/validations.rb
index c1e344b215..6a2668b8f7 100644
--- a/activemodel/lib/active_model/validations.rb
+++ b/activemodel/lib/active_model/validations.rb
@@ -87,7 +87,7 @@ module ActiveModel
         validates_with BlockValidator, _merge_attributes(attr_names), &block
       end
 
-      VALID_OPTIONS_FOR_VALIDATE = [:on, :if, :unless].freeze
+      VALID_OPTIONS_FOR_VALIDATE = [:on, :if, :unless, :prepend].freeze
 
       # Adds a validation method or block to the class. This is useful when
       # overriding the +validate+ instance method becomes too unwieldy and
diff --git a/activemodel/lib/active_model/validations/numericality.rb b/activemodel/lib/active_model/validations/numericality.rb
index 13d6a966c0..4ba4e3e8f7 100644
--- a/activemodel/lib/active_model/validations/numericality.rb
+++ b/activemodel/lib/active_model/validations/numericality.rb
@@ -23,6 +23,10 @@ module ActiveModel
         raw_value = record.send(before_type_cast) if record.respond_to?(before_type_cast)
         raw_value ||= value
 
+        if record_attribute_changed_in_place?(record, attr_name)
+          raw_value = value
+        end
+
         return if options[:allow_nil] && raw_value.nil?
 
         unless value = parse_raw_value_as_a_number(raw_value)
@@ -86,6 +90,13 @@ module ActiveModel
           options[:only_integer]
         end
       end
+
+      private
+
+      def record_attribute_changed_in_place?(record, attr_name)
+        record.respond_to?(:attribute_changed_in_place?) &&
+          record.attribute_changed_in_place?(attr_name.to_s)
+      end
     end
 
     module HelperMethods