feat: Add issuer information to the metadata endpoint, to allow IdPs to properly configure themselves.

Author: suprnova32

lib/omniauth/strategies/saml.rb

@@ -115,6 +115,7 @@ def other_phase
           settings = OneLogin::RubySaml::Settings.new(options)
           if options.request_attributes.length > 0
             settings.attribute_consuming_service.service_name options.attribute_service_name
+            settings.issuer = options.issuer
             options.request_attributes.each do |attribute|
               settings.attribute_consuming_service.add_attribute attribute
             end

spec/omniauth/strategies/saml_spec.rb

@@ -207,6 +207,7 @@ def post_xml(xml=:example_response)
 
   describe 'GET /auth/saml/metadata' do
     before do
+      saml_options[:issuer] = 'http://example.com/SAML'
       get '/auth/saml/metadata'
     end
 
@@ -220,6 +221,8 @@ def post_xml(xml=:example_response)
       expect(last_response.body).to match /first_name/
       expect(last_response.body).to match /last_name/
       expect(last_response.body).to match /Required attributes/
+      expect(last_response.body).to match /entityID/
+      expect(last_response.body).to match /http:\/\/example.com\/SAML/
     end
   end