Merge f7aadef34d into 49cdf0c42e

Fixes #74199

Change-Id: I6a15fbd59a3a3f8c496440f56d09d695e1504e4e
Reviewed-on: https://go-review.googlesource.com/c/go/+/682576
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Alan Donovan <adonovan@google.com>
Auto-Submit: Damien Neil <dneil@google.com>

src/crypto/cipher/gcm.go

@@ -82,7 +82,7 @@ func newGCM(cipher Block, nonceSize, tagSize int) (AEAD, error) {
 
 // NewGCMWithRandomNonce returns the given cipher wrapped in Galois Counter
 // Mode, with randomly-generated nonces. The cipher must have been created by
-// [aes.NewCipher].
+// [crypto/aes.NewCipher].
 //
 // It generates a random 96-bit nonce, which is prepended to the ciphertext by Seal,
 // and is extracted from the ciphertext by Open. The NonceSize of the AEAD is zero,

src/go/doc/testdata/issue62640.0.golden

@@ -0,0 +1,22 @@
+// 
+PACKAGE issue62640
+
+IMPORTPATH
+	testdata/issue62640
+
+FILENAMES
+	testdata/issue62640.go
+
+TYPES
+	// 
+	type E struct{}
+
+	// F should be hidden within S because of the S.F field. 
+	func (E) F()
+
+	// 
+	type S struct {
+		E
+		F	int
+	}
+

src/go/doc/testdata/issue62640.1.golden

@@ -0,0 +1,22 @@
+// 
+PACKAGE issue62640
+
+IMPORTPATH
+	testdata/issue62640
+
+FILENAMES
+	testdata/issue62640.go
+
+TYPES
+	// 
+	type E struct{}
+
+	// F should be hidden within S because of the S.F field. 
+	func (E) F()
+
+	// 
+	type S struct {
+		E
+		F	int
+	}
+

src/go/doc/testdata/issue62640.2.golden

@@ -0,0 +1,25 @@
+// 
+PACKAGE issue62640
+
+IMPORTPATH
+	testdata/issue62640
+
+FILENAMES
+	testdata/issue62640.go
+
+TYPES
+	// 
+	type E struct{}
+
+	// F should be hidden within S because of the S.F field. 
+	func (E) F()
+
+	// 
+	type S struct {
+		E
+		F	int
+	}
+
+	// F should be hidden within S because of the S.F field. 
+	func (S) F()
+

src/go/doc/testdata/issue62640.go

@@ -0,0 +1,15 @@
+// Copyright 2025 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package issue62640
+
+type E struct{}
+
+// F should be hidden within S because of the S.F field.
+func (E) F() {}
+
+type S struct {
+	E
+	F int
+}

src/net/http/http_test.go

@@ -9,6 +9,7 @@ package http
 import (
 	"bytes"
 	"internal/testenv"
+	"io"
 	"io/fs"
 	"net/url"
 	"os"
@@ -189,6 +190,45 @@ func TestNoUnicodeStrings(t *testing.T) {
 	}
 }
 
+type requestTooLargerResponseWriter struct {
+	called bool
+}
+
+func (rw *requestTooLargerResponseWriter) Header() Header              { return Header{} }
+func (rw *requestTooLargerResponseWriter) Write(b []byte) (int, error) { return len(b), nil }
+func (rw *requestTooLargerResponseWriter) WriteHeader(statusCode int)  {}
+func (rw *requestTooLargerResponseWriter) requestTooLarge() {
+	rw.called = true
+}
+
+type wrapper struct {
+	ResponseWriter
+}
+
+func (w *wrapper) Unwrap() ResponseWriter {
+	return w.ResponseWriter
+}
+
+func TestMaxBytesReaderUnwrapTriggersRequestTooLarge(t *testing.T) {
+	body := strings.NewReader("123456")
+	limit := int64(5)
+
+	innerRw := &requestTooLargerResponseWriter{}
+	wrappedRw := &wrapper{ResponseWriter: innerRw}
+
+	l := MaxBytesReader(wrappedRw, io.NopCloser(body), limit)
+
+	buf := make([]byte, 10)
+	_, err := l.Read(buf)
+
+	if _, ok := err.(*MaxBytesError); !ok {
+		t.Errorf("expected MaxBytesError, got %T", err)
+	}
+	if !innerRw.called {
+		t.Errorf("expected requestTooLarge to be called, but it wasn't")
+	}
+}
+
 func TestProtocols(t *testing.T) {
 	var p Protocols
 	if p.HTTP1() {

src/net/http/request.go

@@ -1243,9 +1243,23 @@ func (l *maxBytesReader) Read(p []byte) (n int, err error) {
 	type requestTooLarger interface {
 		requestTooLarge()
 	}
-	if res, ok := l.w.(requestTooLarger); ok {
-		res.requestTooLarge()
+	// Unwrap the ResponseWriter wrappers until we find one that implements
+	// the server-only requestTooLarger interface, then call requestTooLarge().
+	// This ensures that even if the ResponseWriter is wrapped by a custom implementation,
+	// the underlying server writer can be notified when the request body is too large.
+	rw := l.w
+	for {
+		if res, ok := rw.(requestTooLarger); ok {
+			res.requestTooLarge()
+			break
+		}
+		unwrapper, ok := rw.(rwUnwrapper)
+		if !ok {
+			break
+		}
+		rw = unwrapper.Unwrap()
 	}
+
 	l.err = &MaxBytesError{l.i}
 	return n, l.err
 }

src/runtime/mheap.go

@@ -312,8 +312,10 @@ type heapArena struct {
 	// during marking.
 	pageSpecials [pagesPerArena / 8]uint8
 
-	// pageUseSpanDartboard is a bitmap that indicates which spans are
-	// heap spans and also gcUsesSpanDartboard.
+	// pageUseSpanInlineMarkBits is a bitmap where each bit corresponds
+	// to a span, as only spans one page in size can have inline mark bits.
+	// The bit indicates that the span has a spanInlineMarkBits struct
+	// stored directly at the top end of the span's memory.
 	pageUseSpanInlineMarkBits [pagesPerArena / 8]uint8
 
 	// checkmarks stores the debug.gccheckmark state. It is only

src/testing/synctest/helper_test.go

@@ -0,0 +1,15 @@
+// Copyright 2025 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package synctest_test
+
+import "testing"
+
+// helperLog is a t.Helper which logs.
+// Since it is a helper, the log prefix should contain
+// the caller's file, not helper_test.go.
+func helperLog(t *testing.T, s string) {
+	t.Helper()
+	t.Log(s)
+}

src/testing/synctest/synctest_test.go

@@ -140,6 +140,18 @@ func TestRun(t *testing.T) {
 	})
 }
 
+func TestHelper(t *testing.T) {
+	runTest(t, []string{"-test.v"}, func() {
+		synctest.Test(t, func(t *testing.T) {
+			helperLog(t, "log in helper")
+		})
+	}, `^=== RUN   TestHelper
+    synctest_test.go:.* log in helper
+--- PASS: TestHelper.*
+PASS
+$`)
+}
+
 func wantPanic(t *testing.T, want string) {
 	if e := recover(); e != nil {
 		if got := fmt.Sprint(e); got != want {

src/testing/testing.go

@@ -1261,6 +1261,9 @@ func (c *common) Skipped() bool {
 // When printing file and line information, that function will be skipped.
 // Helper may be called simultaneously from multiple goroutines.
 func (c *common) Helper() {
+	if c.isSynctest {
+		c = c.parent
+	}
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	if c.helperPCs == nil {