From 4e7bd20f8fdccdb2f0f30b051e3ea3fffb449367 Mon Sep 17 00:00:00 2001 From: Damien Neil Date: Fri, 5 Jan 2024 16:10:33 -0800 Subject: [PATCH] net/http: remove Content-Length header in http.Error Error replies to a request with an error message and HTTP code. Delete any preexisting Content-Length header before writing the header; if a Content-Length is present, it's probably for content that the caller has given up on writing. For #50905 Change-Id: Ia3d4ca008be46fa5d41afadf29ca5cacb1c47660 Reviewed-on: https://go-review.googlesource.com/c/go/+/554216 Reviewed-by: Brad Fitzpatrick LUCI-TryBot-Result: Go LUCI Reviewed-by: Jonathan Amsterdam --- src/net/http/serve_test.go | 21 +++++++++++++++++++++ src/net/http/server.go | 1 + 2 files changed, 22 insertions(+) diff --git a/src/net/http/serve_test.go b/src/net/http/serve_test.go index 69d105ec63..9df6ab426c 100644 --- a/src/net/http/serve_test.go +++ b/src/net/http/serve_test.go @@ -7052,3 +7052,24 @@ func testDisableContentLength(t *testing.T, mode testMode) { t.Fatal(err) } } + +func TestErrorContentLength(t *testing.T) { run(t, testErrorContentLength) } +func testErrorContentLength(t *testing.T, mode testMode) { + const errorBody = "an error occurred" + cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) { + w.Header().Set("Content-Length", "1000") + Error(w, errorBody, 400) + })) + res, err := cst.c.Get(cst.ts.URL) + if err != nil { + t.Fatalf("Get(%q) = %v", cst.ts.URL, err) + } + defer res.Body.Close() + body, err := io.ReadAll(res.Body) + if err != nil { + t.Fatalf("io.ReadAll(res.Body) = %v", err) + } + if string(body) != errorBody+"\n" { + t.Fatalf("read body: %q, want %q", string(body), errorBody) + } +} diff --git a/src/net/http/server.go b/src/net/http/server.go index 7d73cca43f..bd7cce6793 100644 --- a/src/net/http/server.go +++ b/src/net/http/server.go @@ -2173,6 +2173,7 @@ func (f HandlerFunc) ServeHTTP(w ResponseWriter, r *Request) { // writes are done to w. // The error message should be plain text. func Error(w ResponseWriter, error string, code int) { + w.Header().Del("Content-Length") w.Header().Set("Content-Type", "text/plain; charset=utf-8") w.Header().Set("X-Content-Type-Options", "nosniff") w.WriteHeader(code) -- 2.48.1