Fix :content_type_extension when a style :format is specified.

lib/paperclip/interpolations.rb

@@ -97,9 +97,12 @@ module Paperclip
         File.extname(attachment.original_filename).gsub(/^\.+/, "")
         File.extname(attachment.original_filename).gsub(/^\.+/, "")
     end
     end
 
 
-    # Returns an extension based on the content type. e.g. "jpeg" for "image/jpeg".
+    # Returns an extension based on the content type. e.g. "jpeg" for
+    # "image/jpeg". If the style has a specified format, it will override the
+    # content-type detection.
+    #
     # Each mime type generally has multiple extensions associated with it, so
     # Each mime type generally has multiple extensions associated with it, so
-    # if the extension from teh original filename is one of these extensions,
+    # if the extension from the original filename is one of these extensions,
     # that extension is used, otherwise, the first in the list is used.
     # that extension is used, otherwise, the first in the list is used.
     def content_type_extension attachment, style_name
     def content_type_extension attachment, style_name
       mime_type = MIME::Types[attachment.content_type]
       mime_type = MIME::Types[attachment.content_type]
@@ -110,7 +113,10 @@ module Paperclip
       end
       end
 
 
       original_extension = extension(attachment, style_name)
       original_extension = extension(attachment, style_name)
-      if extensions_for_mime_type.include? original_extension
+      style = attachment.styles[style_name.to_s.to_sym]
+      if style && style[:format]
+        style[:format].to_s
+      elsif extensions_for_mime_type.include? original_extension
         original_extension
         original_extension
       elsif !extensions_for_mime_type.empty?
       elsif !extensions_for_mime_type.empty?
         extensions_for_mime_type.first
         extensions_for_mime_type.first

test/interpolations_test.rb

@@ -56,6 +56,7 @@ class InterpolationsTest < Test::Unit::TestCase
   should "return the extension of the file based on the content type" do
   should "return the extension of the file based on the content type" do
     attachment = mock
     attachment = mock
     attachment.expects(:content_type).returns('image/jpeg')
     attachment.expects(:content_type).returns('image/jpeg')
+    attachment.expects(:styles).returns({})
     interpolations = Paperclip::Interpolations
     interpolations = Paperclip::Interpolations
     interpolations.expects(:extension).returns('random')
     interpolations.expects(:extension).returns('random')
     assert_equal "jpeg", interpolations.content_type_extension(attachment, :style)
     assert_equal "jpeg", interpolations.content_type_extension(attachment, :style)
@@ -64,6 +65,7 @@ class InterpolationsTest < Test::Unit::TestCase
   should "return the original extension of the file if it matches a content type extension" do
   should "return the original extension of the file if it matches a content type extension" do
     attachment = mock
     attachment = mock
     attachment.expects(:content_type).returns('image/jpeg')
     attachment.expects(:content_type).returns('image/jpeg')
+    attachment.expects(:styles).returns({})
     interpolations = Paperclip::Interpolations
     interpolations = Paperclip::Interpolations
     interpolations.expects(:extension).returns('jpe')
     interpolations.expects(:extension).returns('jpe')
     assert_equal "jpe", interpolations.content_type_extension(attachment, :style)
     assert_equal "jpe", interpolations.content_type_extension(attachment, :style)
@@ -72,11 +74,21 @@ class InterpolationsTest < Test::Unit::TestCase
   should "return the latter half of the content type of the extension if no match found" do
   should "return the latter half of the content type of the extension if no match found" do
     attachment = mock
     attachment = mock
     attachment.expects(:content_type).at_least_once().returns('not/found')
     attachment.expects(:content_type).at_least_once().returns('not/found')
+    attachment.expects(:styles).returns({})
     interpolations = Paperclip::Interpolations
     interpolations = Paperclip::Interpolations
     interpolations.expects(:extension).returns('random')
     interpolations.expects(:extension).returns('random')
     assert_equal "found", interpolations.content_type_extension(attachment, :style)
     assert_equal "found", interpolations.content_type_extension(attachment, :style)
   end
   end
 
 
+  should "return the format if defined in the style, ignoring the content type" do
+    attachment = mock
+    attachment.expects(:content_type).returns('image/jpeg')
+    attachment.expects(:styles).returns({:style => {:format => "png"}})
+    interpolations = Paperclip::Interpolations
+    interpolations.expects(:extension).returns('random')
+    assert_equal "png", interpolations.content_type_extension(attachment, :style)
+  end
+
   should "be able to handle numeric style names" do
   should "be able to handle numeric style names" do
     attachment = mock(
     attachment = mock(
       :styles => {:"4" => {:format => :expected_extension}}
       :styles => {:"4" => {:format => :expected_extension}}