Update to go1.24.0

src/bufio/bufio.go

@@ -29,6 +29,9 @@ var (
 // Buffered input.
 
 // Reader implements buffering for an io.Reader object.
+// A new Reader is created by calling [NewReader] or [NewReaderSize];
+// alternatively the zero value of a Reader may be used after calling [Reset]
+// on it.
 type Reader struct {
 	buf          []byte
 	rd           io.Reader // reader provided by the client
@@ -130,9 +133,10 @@ func (b *Reader) readErr() error {
 }
 
 // Peek returns the next n bytes without advancing the reader. The bytes stop
-// being valid at the next read call. If Peek returns fewer than n bytes, it
-// also returns an error explaining why the read is short. The error is
-// [ErrBufferFull] if n is larger than b's buffer size.
+// being valid at the next read call. If necessary, Peek will read more bytes
+// into the buffer in order to make n bytes available. If Peek returns fewer
+// than n bytes, it also returns an error explaining why the read is short.
+// The error is [ErrBufferFull] if n is larger than b's buffer size.
 //
 // Calling Peek prevents a [Reader.UnreadByte] or [Reader.UnreadRune] call from succeeding
 // until the next read operation.

src/bufio/bufio_test.go

@@ -9,6 +9,7 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"internal/asan"
 	"io"
 	"math/rand"
 	"strconv"
@@ -585,6 +586,9 @@ func TestWriteInvalidRune(t *testing.T) {
 }
 
 func TestReadStringAllocs(t *testing.T) {
+	if asan.Enabled {
+		t.Skip("test allocates more with -asan; see #70079")
+	}
 	r := strings.NewReader("       foo       foo        42        42        42        42        42        42        42        42       4.2       4.2       4.2       4.2\n")
 	buf := NewReader(r)
 	allocs := testing.AllocsPerRun(100, func() {
@@ -636,7 +640,7 @@ func TestWriter(t *testing.T) {
 			for l := 0; l < len(written); l++ {
 				if written[l] != data[l] {
 					t.Errorf("wrong bytes written")
-					t.Errorf("want=%q", data[0:len(written)])
+					t.Errorf("want=%q", data[:len(written)])
 					t.Errorf("have=%q", written)
 				}
 			}
@@ -935,7 +939,6 @@ func (t *testReader) Read(buf []byte) (n int, err error) {
 }
 
 func testReadLine(t *testing.T, input []byte) {
-	//for stride := 1; stride < len(input); stride++ {
 	for stride := 1; stride < 2; stride++ {
 		done := 0
 		reader := testReader{input, stride}

src/bufio/example_test.go

@@ -33,6 +33,33 @@ func ExampleWriter_AvailableBuffer() {
 	// Output: 1 2 3 4
 }
 
+// ExampleWriter_ReadFrom demonstrates how to use the ReadFrom method of Writer.
+func ExampleWriter_ReadFrom() {
+	var buf bytes.Buffer
+	writer := bufio.NewWriter(&buf)
+
+	data := "Hello, world!\nThis is a ReadFrom example."
+	reader := strings.NewReader(data)
+
+	n, err := writer.ReadFrom(reader)
+	if err != nil {
+		fmt.Println("ReadFrom Error:", err)
+		return
+	}
+
+	if err = writer.Flush(); err != nil {
+		fmt.Println("Flush Error:", err)
+		return
+	}
+
+	fmt.Println("Bytes written:", n)
+	fmt.Println("Buffer contents:", buf.String())
+	// Output:
+	// Bytes written: 41
+	// Buffer contents: Hello, world!
+	// This is a ReadFrom example.
+}
+
 // The simplest use of a Scanner, to read standard input as a set of lines.
 func ExampleScanner_lines() {
 	scanner := bufio.NewScanner(os.Stdin)