Revert "handle nil content-disposition in tii"

This reverts commit 5fb3bac09e.

Change-Id: I817271b8d7c78f0e1efedb656e480d906a003fc3
Reviewed-on: https://gerrit.instructure.com/135453
Tested-by: Jenkins
Reviewed-by: Ryan Shaw <ryan@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>

lib/turnitin/attachment_manager.rb

@@ -41,8 +41,7 @@ module Turnitin
     def self.save_attachment(turnitin_client, user, attachment)
       Dir.mktmpdir do |dirname|
         turnitin_client.original_submission do |response|
-          filename = 'default_filename.txt' if response.headers['content-disposition'].nil?
-          filename ||= response.headers['content-disposition'].match(/filename=(\"?)(.+)\1/)[2]
+          filename = response.headers['content-disposition'].match(/filename=(\"?)(.+)\1/)[2]
           filename.tr!('/','-')
           path = File.join(dirname, filename)
           File.open(path, 'wb') do |f|

spec/lib/turnitin/attachment_manager_spec.rb

@@ -43,24 +43,6 @@ module Turnitin
 
     end
 
-    describe 'invalid response' do
-      let(:response_mock) do
-        r_mock = double('response')
-        allow(r_mock).to receive(:headers).
-          and_return({
-                       'content-disposition' => nil,
-                       'content-type' => 'plain/text'
-                     })
-        allow(r_mock).to receive(:body).and_return('abcdef')
-        r_mock
-      end
-
-      it 'does not crash when there is no content-disposition' do
-        subject.class.create_attachment(lti_student, lti_assignment, tool, outcome_response_json)
-        expect(lti_assignment.attachments.first.display_name).to eq 'default_filename.txt'
-      end
-    end
-
     describe '.update_attachment' do
       let(:submission) do
         sub = lti_assignment.submit_homework(