Updating golang dependancies (#4075)

vendor/github.com/go-sql-driver/mysql/buffer.go

@@ -8,11 +8,7 @@
 
 package mysql
 
-import (
-	"io"
-	"net"
-	"time"
-)
+import "io"
 
 const defaultBufSize = 4096
 
@@ -22,28 +18,25 @@ const defaultBufSize = 4096
 // The buffer is similar to bufio.Reader / Writer but zero-copy-ish
 // Also highly optimized for this particular use case.
 type buffer struct {
-	buf     []byte
-	nc      net.Conn
-	idx     int
-	length  int
-	timeout time.Duration
+	buf    []byte
+	rd     io.Reader
+	idx    int
+	length int
 }
 
-func newBuffer(nc net.Conn) buffer {
+func newBuffer(rd io.Reader) buffer {
 	var b [defaultBufSize]byte
 	return buffer{
 		buf: b[:],
-		nc:  nc,
+		rd:  rd,
 	}
 }
 
 // fill reads into the buffer until at least _need_ bytes are in it
 func (b *buffer) fill(need int) error {
-	n := b.length
-
 	// move existing data to the beginning
-	if n > 0 && b.idx > 0 {
-		copy(b.buf[0:n], b.buf[b.idx:])
+	if b.length > 0 && b.idx > 0 {
+		copy(b.buf[0:b.length], b.buf[b.idx:])
 	}
 
 	// grow buffer if necessary
@@ -59,33 +52,19 @@ func (b *buffer) fill(need int) error {
 	b.idx = 0
 
 	for {
-		if b.timeout > 0 {
-			if err := b.nc.SetReadDeadline(time.Now().Add(b.timeout)); err != nil {
-				return err
-			}
-		}
+		n, err := b.rd.Read(b.buf[b.length:])
+		b.length += n
 
-		nn, err := b.nc.Read(b.buf[n:])
-		n += nn
-
-		switch err {
-		case nil:
-			if n < need {
+		if err == nil {
+			if b.length < need {
 				continue
 			}
-			b.length = n
 			return nil
-
-		case io.EOF:
-			if n >= need {
-				b.length = n
-				return nil
-			}
-			return io.ErrUnexpectedEOF
-
-		default:
-			return err
 		}
+		if b.length >= need && err == io.EOF {
+			return nil
+		}
+		return err
 	}
 }