Fix read timing and test case

benchmarks/bench_test.go

@@ -14,6 +14,7 @@ import (
 	"bytes"
 	"compress/gzip"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"os"
 	"strings"
@@ -373,9 +374,11 @@ func BenchmarkCodeDecoder(b *testing.B) {
 			buf.WriteByte('\n')
 			buf.WriteByte('\n')
 			if err := dec.Decode(&r); err != nil {
+				if err != io.EOF {
 					b.Fatal("Decode:", err)
 				}
 			}
+		}
 	})
 	b.SetBytes(int64(len(codeJSON)))
 }
@@ -390,8 +393,10 @@ func BenchmarkUnicodeDecoder(b *testing.B) {
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
 		if err := dec.Decode(&out); err != nil {
+			if err != io.EOF {
 				b.Fatal("Decode:", err)
 			}
+		}
 		r.Seek(0, 0)
 	}
 }
@@ -414,10 +419,12 @@ func BenchmarkDecoderStream(b *testing.B) {
 		}
 		x = nil
 		if err := dec.Decode(&x); err != nil || x != 1.0 {
+			if err != io.EOF {
 				b.Fatalf("Decode: %v after %d", err, i)
 			}
 		}
 	}
+}
 
 func BenchmarkCodeUnmarshal(b *testing.B) {
 	b.ReportAllocs()

decode.go

@@ -61,7 +61,6 @@ const (
 // read data from r beyond the JSON values requested.
 func NewDecoder(r io.Reader) *Decoder {
 	s := newStream(r)
-	s.read()
 	return &Decoder{
 		s: s,
 	}

decode_stream.go

@@ -26,6 +26,7 @@ func newStream(r io.Reader) *stream {
 	return &stream{
 		r:       r,
 		bufSize: initBufSize,
+		buf:     []byte{nul},
 	}
 }