Fixed bug when exists? called and original_filename is nil

lib/paperclip/storage.rb

@@ -6,7 +6,11 @@ module Paperclip
       end
       
       def exists?(style = default_style)
-        File.exist?(path(style))
+        if original_filename
+          File.exist?(path(style))
+        else
+          false
+        end
       end
 
       # Returns representation of the data of the file assigned to the given

test/test_attachment.rb

@@ -28,6 +28,16 @@ class AttachmentTest < Test::Unit::TestCase
       end
     end
 
+    context "without an Attachment" do
+      setup do
+        @dummy = Dummy.new
+      end
+      
+      should "return false when asked exists?" do
+        assert !@dummy.avatar.exists?
+      end
+    end
+
     context "on an Attachment" do
       setup do
         @dummy = Dummy.new