FIX: broken mailto href's in emails

lib/pretty_text.rb

@@ -360,7 +360,9 @@ module PrettyText
       begin
         uri = URI(href)
         site_uri ||= URI(Discourse.base_url)
-        link["href"] = "#{site_uri}#{link['href']}" unless uri.host.present?
+        unless uri.host.present? || href.start_with?('mailto')
+          link["href"] = "#{site_uri}#{link['href']}"
+	end
       rescue URI::InvalidURIError, URI::InvalidComponentError
         # leave it
       end

spec/components/pretty_text_spec.rb

@@ -628,6 +628,11 @@ describe PrettyText do
       html = "<p>Check out <a href=\"not a real url\">this guy</a>.</p>"
       expect { described_class.format_for_email(html, post) }.to_not raise_error
     end
+
+    it "doesn't change mailto" do
+      html = "<p>Contact me at <a href=\"mailto:username@me.com\">this address</a>.</p>"
+      expect(PrettyText.format_for_email(html, post)).to eq(html)
+    end
   end
 
   it 'Is smart about linebreaks and IMG tags' do