move gotd fork into repo. (#111)

- update to latest telegram layer
- remove some references to fields in tg.Entities that don't exist in
the schema
- originally added here:
https://github.com/beeper/td/commit/820929062a2ba0104397bc01235ab58a9cff780e
  - referenced here
-
https://github.com/mautrix/telegramgo/commit/124f0967ed195b5a380c9bd02e170ada9710dde3
-
https://github.com/mautrix/telegramgo/commit/4205047aab2e0639217148b5d125bfaab668bd8e

pkg/gotd/bin/buffer_test.go

@@ -0,0 +1,110 @@
+package bin
+
+import (
+	"io"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"go.mau.fi/mautrix-telegram/pkg/gotd/testutil"
+)
+
+func TestExpandReset(t *testing.T) {
+	a := require.New(t)
+	b := Buffer{}
+	b.PutInt(10)
+	before := b.Len()
+	copyBuf := b.Copy()
+
+	b.Expand(2)
+	a.Equal(before+2, b.Len())
+	a.Equal(copyBuf, b.Buf[:before], "buffer overwrite")
+
+	b.ResetN(b.Len() + 2)
+	a.Zero(b.Buf[0], "buffer not zeroed")
+
+	before = b.Len()
+	b.Skip(2)
+	a.Equal(before-2, b.Len())
+}
+
+func TestCopy(t *testing.T) {
+	b := Buffer{}
+	b.PutInt(10)
+	copyBuf := b.Copy()
+	copyBuf[0] = 1
+	require.Equal(t, byte(10), b.Buf[0], "buffer overwritten from copy")
+}
+
+func TestBuffer_ResetN(t *testing.T) {
+	var b Buffer
+	testutil.ZeroAlloc(t, func() {
+		b.ResetN(1024)
+	})
+}
+
+func TestBuffer_Raw(t *testing.T) {
+	b := Buffer{Buf: []byte{1, 2, 3}}
+	b.Raw()[0] = 2
+	require.Equal(t, []byte{2, 2, 3}, b.Buf)
+}
+
+func TestBuffer_ResetTo(t *testing.T) {
+	orig := []byte{1, 2, 3}
+	b := Buffer{Buf: orig}
+
+	b.ResetTo([]byte{4, 5, 6})
+	b.Buf[0] = 2
+
+	require.Equal(t, []byte{1, 2, 3}, orig)
+	require.Equal(t, []byte{2, 5, 6}, b.Buf)
+}
+
+var errTest = testutil.TestError()
+
+type errObject struct{}
+
+func (e errObject) Encode(b *Buffer) error {
+	return errTest
+}
+
+func (e errObject) Decode(b *Buffer) error {
+	return errTest
+}
+
+type bytesObject uint32
+
+func (o bytesObject) Decode(b *Buffer) error {
+	return b.ConsumeID(uint32(o))
+}
+
+func (o bytesObject) Encode(b *Buffer) error {
+	b.PutUint32(uint32(o))
+	return nil
+}
+
+func TestBufferEncodeDecode(t *testing.T) {
+	a := require.New(t)
+	b := Buffer{}
+	a.ErrorIs(b.Encode(errObject{}), errTest)
+	a.ErrorIs(b.Decode(errObject{}), errTest)
+	a.NoError(b.Encode(bytesObject(1)))
+	a.NoError(b.Decode(bytesObject(1)))
+}
+
+func TestBuffer_Read(t *testing.T) {
+	a := require.New(t)
+	b := Buffer{}
+
+	_, err := b.Read(nil)
+	a.NoError(err)
+
+	_, err = b.Read([]byte{1})
+	a.ErrorIs(err, io.EOF)
+	a.Equal(err, io.EOF)
+
+	b.Put([]byte{1})
+	_, err = b.Read([]byte{1})
+	a.NoError(err)
+	a.Empty(b.Buf)
+}