Wrap mock_call in rescue

lib/omniauth/strategy.rb

@@ -298,8 +298,13 @@ def options_request?
     # in the event that OmniAuth has been configured to be
     # in test mode.
     def mock_call!(*)
-      return mock_request_call if on_request_path? && OmniAuth.config.allowed_request_methods.include?(request.request_method.downcase.to_sym)
-      return mock_callback_call if on_callback_path?
+      begin
+        OmniAuth.config.request_validation_phase.call(env) if OmniAuth.config.request_validation_phase
+        return mock_request_call if on_request_path? && OmniAuth.config.allowed_request_methods.include?(request.request_method.downcase.to_sym)
+        return mock_callback_call if on_callback_path?
+      rescue StandardError => e
+        return fail!(e.message, e)
+      end
 
       call_app!
     end

spec/omniauth/strategy_spec.rb

@@ -885,6 +885,12 @@ def make_env(path = '/auth/test', props = {})
         expect(strategy.env['omniauth.params']).to eq('foo' => 'bar')
       end
 
+      it 'rescues errors in request_call' do
+        allow(strategy).to receive(:mock_request_call).and_raise(StandardError.new('Oh no'))
+        expect(strategy).to receive(:fail!).with('Oh no', kind_of(StandardError))
+        strategy.call(make_env)
+      end
+
       after do
         OmniAuth.config.test_mode = false
       end