not escape to timestamp

@see https://github.com/thoughtbot/paperclip/commit/804b4edc1d8d7ca9865170e34f26da7d66f6d0d5#commitcomment-8497017

lib/paperclip/url_generator.rb

@@ -8,8 +8,8 @@ module Paperclip
     end
 
     def for(style_name, options)
-      escape_url_as_needed(
-        timestamp_as_needed(
+      timestamp_as_needed(
+        escape_url_as_needed(
           @attachment_options[:interpolator].interpolate(most_appropriate_url, @attachment, style_name),
           options
       ), options)

spec/paperclip/url_generator_spec.rb

@@ -184,16 +184,30 @@ describe Paperclip::UrlGenerator do
       "expected the interpolator to be passed #{expected.inspect} but it wasn't"
   end
 
-  it "should be able to escape (, ), [, and ]." do
-    expected = "the(expected)result[]"
-    mock_attachment = MockAttachment.new
-    mock_interpolator = MockInterpolator.new(result: expected)
-    options = { interpolator: mock_interpolator }
-    url_generator = Paperclip::UrlGenerator.new(mock_attachment, options)
-    def url_generator.respond_to(params)
-      false if params == :escape
+  describe "should be able to escape (, ), [, and ]." do
+    def generate(expected, updated_at=nil)
+      mock_attachment = MockAttachment.new(updated_at: updated_at)
+      mock_interpolator = MockInterpolator.new(result: expected)
+      options = { interpolator: mock_interpolator }
+      url_generator = Paperclip::UrlGenerator.new(mock_attachment, options)
+      def url_generator.respond_to(params)
+        false if params == :escape
+      end
+      if updated_at
+        url_generator.for(:style_name, {escape: true, timestamp: true})
+      else
+        url_generator.for(:style_name, {escape: true})
+      end
+    end
+    it "not timestamp" do
+      expected = "the(expected)result[]"
+      assert_equal "the%28expected%29result%5B%5D", generate(expected)
+    end
+    it "timestamp" do
+      expected = "the(expected)result[]"
+      updated_at = 1231231234
+      assert_equal "the%28expected%29result%5B%5D?#{updated_at}", generate(expected, updated_at)
     end
-    result = url_generator.for(:style_name, {escape: true})
-    assert_equal "the%28expected%29result%5B%5D", result
   end
+
 end