12 files changed, 3 insertions, 17 deletions
diff --git a/activemodel/lib/active_model/attribute_methods.rb b/activemodel/lib/active_model/attribute_methods.rb
index eb06250060..21b1209875 100644
--- a/activemodel/lib/active_model/attribute_methods.rb
+++ b/activemodel/lib/active_model/attribute_methods.rb
@@ -1,5 +1,3 @@
-require 'active_support/core_ext/class/attribute'
-require 'active_support/deprecation'
 
 module ActiveModel
   # Raised when an attribute is not defined.
diff --git a/activemodel/lib/active_model/conversion.rb b/activemodel/lib/active_model/conversion.rb
index 57b1bc2ada..48c53f0789 100644
--- a/activemodel/lib/active_model/conversion.rb
+++ b/activemodel/lib/active_model/conversion.rb
@@ -1,4 +1,3 @@
-require 'active_support/concern'
 require 'active_support/inflector'
 
 module ActiveModel
diff --git a/activemodel/lib/active_model/dirty.rb b/activemodel/lib/active_model/dirty.rb
index 9bd5f903cd..c0b268fa4d 100644
--- a/activemodel/lib/active_model/dirty.rb
+++ b/activemodel/lib/active_model/dirty.rb
@@ -1,7 +1,6 @@
 require 'active_model/attribute_methods'
 require 'active_support/hash_with_indifferent_access'
 require 'active_support/core_ext/object/duplicable'
-require 'active_support/core_ext/object/blank'
 
 module ActiveModel
   # == Active Model Dirty
diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 4ed3462e7e..d68086584e 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -2,7 +2,6 @@
 
 require 'active_support/core_ext/array/conversions'
 require 'active_support/core_ext/string/inflections'
-require 'active_support/core_ext/object/blank'
 
 module ActiveModel
   # == Active Model Errors
diff --git a/activemodel/lib/active_model/mass_assignment_security.rb b/activemodel/lib/active_model/mass_assignment_security.rb
index e57fcf1610..87c0bcf59b 100644
--- a/activemodel/lib/active_model/mass_assignment_security.rb
+++ b/activemodel/lib/active_model/mass_assignment_security.rb
@@ -1,4 +1,3 @@
-require 'active_support/core_ext/class/attribute'
 require 'active_support/core_ext/string/inflections'
 require 'active_model/mass_assignment_security/permission_set'
 require 'active_model/mass_assignment_security/sanitizer'
diff --git a/activemodel/lib/active_model/naming.rb b/activemodel/lib/active_model/naming.rb
index ea4f9341c6..af89391413 100644
--- a/activemodel/lib/active_model/naming.rb
+++ b/activemodel/lib/active_model/naming.rb
@@ -1,8 +1,6 @@
 require 'active_support/inflector'
 require 'active_support/core_ext/hash/except'
 require 'active_support/core_ext/module/introspection'
-require 'active_support/core_ext/module/delegation'
-require 'active_support/core_ext/object/blank'
 
 module ActiveModel
   class Name
diff --git a/activemodel/lib/active_model/observing.rb b/activemodel/lib/active_model/observing.rb
index 976dcf23d8..acc96ddc9f 100644
--- a/activemodel/lib/active_model/observing.rb
+++ b/activemodel/lib/active_model/observing.rb
@@ -4,7 +4,6 @@ require 'active_support/core_ext/module/aliasing'
 require 'active_support/core_ext/module/remove_method'
 require 'active_support/core_ext/string/inflections'
 require 'active_support/core_ext/enumerable'
-require 'active_support/deprecation'
 require 'active_support/core_ext/object/try'
 require 'active_support/descendants_tracker'
 
@@ -215,7 +214,7 @@ module ActiveModel
       #     end
       #   end
       def observed_classes
-        [observed_class].compact.flatten
+        Array(observed_class)
       end
 
       # The class observed by default is inferred from the observer's class name:
diff --git a/activemodel/lib/active_model/secure_password.rb b/activemodel/lib/active_model/secure_password.rb
index 3eab745c89..dc89efd2d1 100644
--- a/activemodel/lib/active_model/secure_password.rb
+++ b/activemodel/lib/active_model/secure_password.rb
@@ -43,9 +43,9 @@ module ActiveModel
         if options.fetch(:validations, true)
           validates_confirmation_of :password
           validates_presence_of     :password, :on => :create
+          
+          before_create { raise "Password digest missing on new record" if password_digest.blank? }
         end
-        
-        before_create { raise "Password digest missing on new record" if password_digest.blank? }
 
         include InstanceMethodsOnActivation
 
diff --git a/activemodel/lib/active_model/serializers/json.rb b/activemodel/lib/active_model/serializers/json.rb
index e4c7553cb8..eaea0475ad 100644
--- a/activemodel/lib/active_model/serializers/json.rb
+++ b/activemodel/lib/active_model/serializers/json.rb
@@ -1,5 +1,4 @@
 require 'active_support/json'
-require 'active_support/core_ext/class/attribute'
 
 module ActiveModel
   # == Active Model JSON Serializer
diff --git a/activemodel/lib/active_model/validations.rb b/activemodel/lib/active_model/validations.rb
index 55ea6be796..5ae3a97c6b 100644
--- a/activemodel/lib/active_model/validations.rb
+++ b/activemodel/lib/active_model/validations.rb
@@ -1,5 +1,4 @@
 require 'active_support/core_ext/array/extract_options'
-require 'active_support/core_ext/class/attribute'
 require 'active_support/core_ext/hash/keys'
 require 'active_support/core_ext/hash/except'
 require 'active_model/errors'
diff --git a/activemodel/lib/active_model/validations/presence.rb b/activemodel/lib/active_model/validations/presence.rb
index 4592a1deb0..f159e40858 100644
--- a/activemodel/lib/active_model/validations/presence.rb
+++ b/activemodel/lib/active_model/validations/presence.rb
@@ -1,4 +1,3 @@
-require 'active_support/core_ext/object/blank'
 
 module ActiveModel
 
diff --git a/activemodel/lib/active_model/validator.rb b/activemodel/lib/active_model/validator.rb
index d5d0798704..cbbf58505b 100644
--- a/activemodel/lib/active_model/validator.rb
+++ b/activemodel/lib/active_model/validator.rb
@@ -1,6 +1,4 @@
 require "active_support/core_ext/module/anonymous"
-require 'active_support/core_ext/object/blank'
-require 'active_support/core_ext/object/inclusion'
 
 module ActiveModel #:nodoc: