Fix warnings seen in delayed_paperclip tests

lib/paperclip/attachment.rb

@@ -219,6 +219,7 @@ module Paperclip
 
     # Returns true if there are changes that need to be saved.
     def dirty?
+      return false unless defined?(@dirty)
       @dirty || false
     end
 
@@ -338,9 +339,11 @@ module Paperclip
     # for more details.
     def instance_read(attr)
       getter = :"#{name}_#{attr}"
+      if instance_variable_defined?("@_#{getter}")
+        cached = self.instance_variable_get("@_#{getter}")
+        return cached if cached
+      end
       responds = instance.respond_to?(getter)
-      cached = self.instance_variable_get("@_#{getter}")
-      return cached if cached
       instance.send(getter) if responds || attr.to_s == "file_name"
     end
 
@@ -363,13 +366,14 @@ module Paperclip
     end
 
     def validate #:nodoc:
-      return if @validated
-      self.class.validations.each do |validation|
-        name, options = validation
-        error = send(:"validate_#{name}", options) if allow_validation?(options)
-        errors[name] = error if error
+      @validated ||= begin
+        self.class.validations.each do |validation|
+          name, options = validation
+          error = send(:"validate_#{name}", options) if allow_validation?(options)
+          errors[name] = error if error
+        end
+        true
       end
-      @validated = true
     end
 
     def allow_validation? options #:nodoc:

lib/paperclip/callback_compatability.rb

@@ -45,7 +45,7 @@ module Paperclip
           end
 
         def define_paperclip_callbacks(*callbacks)
-          define_callbacks *callbacks.flatten, CALLBACK_OPTIONS
+          define_callbacks(*callbacks.flatten, CALLBACK_OPTIONS)
           callbacks.map(&:to_sym).each do |callback|
             define_singleton_method "before_#{callback}" do |*args, &blk|
               set_callback(callback, :before, *args, &blk)

lib/paperclip/geometry.rb

@@ -27,7 +27,7 @@ module Paperclip
       file = file.path if file.respond_to? "path"
       geometry = begin
                    Paperclip.run("identify", %Q[-format "%wx%h,%[exif:orientation]" "#{file}"[0]])
-                 rescue PaperclipCommandLineError => e
+                 rescue PaperclipCommandLineError
                    ""
                  end
       parse(geometry) ||

lib/paperclip/thumbnail.rb

@@ -58,7 +58,7 @@ module Paperclip
       end_command
 
       begin
-        success = Paperclip.run("convert", command.gsub(/\s+/, " "))
+        _success = Paperclip.run("convert", command.gsub(/\s+/, " "))
       rescue PaperclipCommandLineError
         raise PaperclipError, "There was an error processing the thumbnail for #{@basename}" if @whiny
       end
@@ -90,7 +90,7 @@ module Paperclip
         raise PaperclipError, "There was an error processing the thumbnail for #{@basename}" if @whiny
       end
 
-      magick, type = result.split("\n")
+      magick, _type = result.split("\n")
       if magick == 'PNG'
         '-define png:big-depth=16 -define png:color-type=6'
       else

lib/paperclip/upfile.rb

@@ -47,7 +47,7 @@ end
 
 if defined? StringIO
   class StringIO
-    attr_accessor :original_filename, :content_type
+    attr_writer :original_filename, :content_type
 
     def original_filename
       @original_filename ||= "stringio.txt"