undo CL 13004046 / 5db14b33d6ef

Flushing after every token negates the point of buffering. A different approach is required.

««« original CL description
encoding/xml: flush buffer after encoding token

R=rsc, bradfitz, adg
CC=golang-dev
https://golang.org/cl/13004046

»»»

R=golang-dev, adg, rsc
CC=golang-dev
https://golang.org/cl/13515043

src/pkg/encoding/xml/marshal.go

@@ -196,6 +196,7 @@ func (enc *Encoder) EncodeToken(t Token) error {
 		p.WriteString("<!--")
 		p.Write(t)
 		p.WriteString("-->")
+		return p.cachedWriteError()
 	case ProcInst:
 		if t.Target == "xml" || !isNameString(t.Target) {
 			return fmt.Errorf("xml: EncodeToken of ProcInst with invalid Target")
@@ -218,7 +219,7 @@ func (enc *Encoder) EncodeToken(t Token) error {
 		p.Write(t)
 		p.WriteString(">")
 	}
-	return p.Flush()
+	return p.cachedWriteError()
 }
 
 type printer struct {

src/pkg/encoding/xml/marshal_test.go

@@ -1076,15 +1076,6 @@ func TestMarshalWriteIOErrors(t *testing.T) {
 	}
 }
 
-func TestEncodeTokenFlush(t *testing.T) {
-	var buf bytes.Buffer
-	enc := NewEncoder(&buf)
-	enc.EncodeToken(StartElement{Name: Name{Local: "some-tag"}})
-	if g, w := buf.String(), "<some-tag>"; g != w {
-		t.Errorf("Encoder wrote %q, want %q", g, w)
-	}
-}
-
 func BenchmarkMarshal(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		Marshal(atomValue)