From: Damien Neil <dneil@google.com>
Date: Mon, 8 Apr 2024 18:43:03 +0000 (-0700)
Subject: net/http: update HandlerWritesTooMuch test to allow different h1/h2 behavior
X-Git-Tag: go1.23rc1~669
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=50a5059056e2233c5112e1dbb65c19bfc79ebb5d;p=gostls13.git

net/http: update HandlerWritesTooMuch test to allow different h1/h2 behavior

Rather than requiring that HTTP/1 and HTTP/2 servers behave identically
when a misbehaving handler writes too many bytes, check only that both
behave reasonably.

In particular, allow the handler to defer detection of a write overrun
until flush time, and permit the HTTP/2 handler to reset the stream
rather than requring it to return a truncated body as HTTP/1 must.

For #56019

Change-Id: I0838e550c4fc202dcbb8bf39ce0fa4a367ca7e71
Reviewed-on: https://go-review.googlesource.com/c/go/+/577415
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
---

diff --git a/src/net/http/clientserver_test.go b/src/net/http/clientserver_test.go
index 32948f3aed..1fe4eed3f7 100644
--- a/src/net/http/clientserver_test.go
+++ b/src/net/http/clientserver_test.go
@@ -510,19 +510,35 @@ func TestH12_HandlerWritesTooLittle(t *testing.T) {
 // doesn't make it possible to send bogus data. For those tests, see
 // transport_test.go (for HTTP/1) or x/net/http2/transport_test.go
 // (for HTTP/2).
-func TestH12_HandlerWritesTooMuch(t *testing.T) {
-	h12Compare{
-		Handler: func(w ResponseWriter, r *Request) {
-			w.Header().Set("Content-Length", "3")
-			w.(Flusher).Flush()
-			io.WriteString(w, "123")
-			w.(Flusher).Flush()
-			n, err := io.WriteString(w, "x") // too many
-			if n > 0 || err == nil {
-				t.Errorf("for proto %q, final write = %v, %v; want 0, some error", r.Proto, n, err)
-			}
-		},
-	}.run(t)
+func TestHandlerWritesTooMuch(t *testing.T) { run(t, testHandlerWritesTooMuch) }
+func testHandlerWritesTooMuch(t *testing.T, mode testMode) {
+	wantBody := []byte("123")
+	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
+		rc := NewResponseController(w)
+		w.Header().Set("Content-Length", fmt.Sprintf("%v", len(wantBody)))
+		rc.Flush()
+		w.Write(wantBody)
+		rc.Flush()
+		n, err := io.WriteString(w, "x") // too many
+		if err == nil {
+			err = rc.Flush()
+		}
+		// TODO: Check that this is ErrContentLength, not just any error.
+		if err == nil {
+			t.Errorf("for proto %q, final write = %v, %v; want _, some error", r.Proto, n, err)
+		}
+	}))
+
+	res, err := cst.c.Get(cst.ts.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer res.Body.Close()
+
+	gotBody, _ := io.ReadAll(res.Body)
+	if !bytes.Equal(gotBody, wantBody) {
+		t.Fatalf("got response body: %q; want %q", gotBody, wantBody)
+	}
 }
 
 // Verify that both our HTTP/1 and HTTP/2 request and auto-decompress gzip.