Revert "Remove bad mailto links"

This reverts commit 77f62a52a6.

refs LS-2622

Change-Id: Ie73c00fffbf1fc2f62448797ca0022feed8998bc
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/273715
Reviewed-by: Jeremy Stanley <jeremy@instructure.com>
QA-Review: Jeremy Stanley <jeremy@instructure.com>
Product-Review: Jeremy Stanley <jeremy@instructure.com>
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>

lib/user_content.rb

@@ -212,15 +212,6 @@ module UserContent
 
       asset_types = AssetTypes.reject { |k,v| !@allowed_types.include?(k) }
 
-      # Remove any bad mailto links
-      doc = Nokogiri::HTML5.fragment(html)
-      doc.css('a[href^="mailto:"]').each do |mailto|
-        email = mailto['href'][7..]
-        next if EmailAddressValidator.valid?(email)
-
-        html = html.gsub(mailto.to_html, mailto.text)
-      end
-
       html.gsub(@toplevel_regex) do |url|
         _absolute_part, prefix, type, obj_id, rest = [$1, $2, $3, $4, $5]
         next url if !@contextless_types.include?(type) && prefix != @context_prefix && url != @context_prefix

spec/lib/cc/cc_helper_spec.rb

@@ -303,18 +303,5 @@ describe CC::CCHelper do
         HTML
       }.not_to raise_error
     end
-
-    it "should remove invalid mailto links" do
-      @exporter = CC::CCHelper::HtmlContentExporter.new(@course, @user, :for_course_copy => true)
-      html = %{
-        <a href="mailto:.">bad mailto</a>
-        <a href="mailto:good@test.test">good mailto</a>
-      }
-      translated = @exporter.html_content(html)
-      expect(translated).to eq %{
-        bad mailto
-        <a href="mailto:good@test.test">good mailto</a>
-      }
-    end
   end
 end