http3: close the connection when closing the roundtripper (#3873)

http3/roundtrip.go

@@ -239,7 +239,12 @@ func (r *RoundTripper) Close() error {
 	}
 	r.clients = nil
 	if r.transport != nil {
-		r.transport.Close()
+		if err := r.transport.Close(); err != nil {
+			return err
+		}
+		if err := r.transport.Conn.Close(); err != nil {
+			return err
+		}
 		r.transport = nil
 	}
 	return nil

integrationtests/self/hotswap_test.go

@@ -98,7 +98,7 @@ var _ = Describe("HTTP3 Server hotswap test", func() {
 	})
 
 	AfterEach(func() {
-		rt.Close()
+		Expect(rt.Close()).NotTo(HaveOccurred())
 		Expect(ln.Close()).NotTo(HaveOccurred())
 	})
 

integrationtests/self/http_test.go

@@ -106,7 +106,7 @@ var _ = Describe("HTTP tests", func() {
 	})
 
 	AfterEach(func() {
-		rt.Close()
+		Expect(rt.Close()).NotTo(HaveOccurred())
 		Expect(server.Close()).NotTo(HaveOccurred())
 		Eventually(stoppedServing).Should(BeClosed())
 	})