Fixed size and content type validations to not care about presence.

lib/paperclip.rb

@@ -305,7 +305,8 @@ module Paperclip
                              :in        => range,
                              :message   => message,
                              :if        => options[:if],
-                             :unless  => options[:unless]
+                             :unless    => options[:unless],
+                             :allow_nil => true
     end
 
     # Adds errors if thumbnail creation fails. The same as specifying :whiny_thumbnails => true.
@@ -346,11 +347,12 @@ module Paperclip
     # model, content_type validation will work _ONLY upon assignment_ and
     # re-validation after the instance has been reloaded will always succeed.
     def validates_attachment_content_type name, options = {}
-      types = [options.delete(:content_type)].flatten
-      validates_each(:"#{name}_content_type", options) do |record, attr, value|
-        unless types.any?{|t| t === value }
+      validation_options = options.dup
+      allowed_types = [validation_options[:content_type]].flatten
+      validates_each(:"#{name}_content_type", validation_options) do |record, attr, value|
+        if !allowed_types.any?{|t| t === value } && value.present?
           if record.errors.method(:add).arity == -2
-            message = options[:message] || "is not one of #{types.join(", ")}"
+            message = options[:message] || "is not one of #{allowed_types.join(", ")}"
             record.errors.add(:"#{name}_content_type", message)
           else
             record.errors.add(:"#{name}_content_type", :inclusion, :default => options[:message], :value => value)

test/paperclip_test.rb

@@ -245,6 +245,7 @@ class PaperclipTest < Test::Unit::TestCase
     def self.should_validate validation, options, valid_file, invalid_file
       context "with #{validation} validation and #{options.inspect} options" do
         setup do
+          rebuild_class
           Dummy.send(:"validates_attachment_#{validation}", :avatar, options)
           @dummy = Dummy.new
         end
@@ -259,7 +260,7 @@ class PaperclipTest < Test::Unit::TestCase
             end
           else
             should "not have an error on the attachment" do
-              assert @dummy.errors[:avatar_file_name].blank?, @dummy.errors.full_messages.join(", ")
+              assert @dummy.errors.blank?, @dummy.errors.full_messages.join(", ")
             end
           end
         end