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)