Restore the outer profiler context after a nested request on the same thread

lib/mini_profiler.rb

@@ -163,6 +163,7 @@ def tool_disabled_message(client_settings)
 
     def call(env)
       start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+      outer_context = current
       client_settings = ClientSettings.new(env, @storage, start)
       MiniProfiler.deauthorize_request if @config.authorization_mode == :allow_authorized
 
@@ -415,8 +416,8 @@ def call(env)
 
       client_settings.handle_cookie([status, headers, body])
     ensure
-      # Make sure this always happens
-      self.current = nil
+      # Make sure this always happens, restoring the context of an outer request on the same thread
+      self.current = outer_context
     end
 
     def matches_action?(action, env)

spec/integration/mini_profiler_spec.rb

@@ -717,4 +717,18 @@ def load_prof(response)
       expect(last_response.body).to include('This is the help menu')
     end
   end
+
+  describe 'with a nested request on the same thread' do
+    it 'keeps the outer request profiled' do
+      inner = Rack::MiniProfiler.new(lambda { |env| [200, { Rack::CONTENT_TYPE => 'text/html' }, +'<h1>inner</h1>'] })
+      outer = Rack::MiniProfiler.new(lambda { |env|
+        Rack::MockRequest.new(inner).get('/inner')
+        [200, { Rack::CONTENT_TYPE => 'text/html' }, +'<html><body><h1>outer</h1></body></html>']
+      })
+
+      response = Rack::MockRequest.new(outer).get('/outer')
+      expect(response.status).to eq(200)
+      expect(response.body).to include('mini-profiler')
+    end
+  end
 end