From ed90fbc747b384a355ded46ff5c9164ca69b6590 Mon Sep 17 00:00:00 2001
From: Brad Fitzpatrick <bradfitz@golang.org>
Date: Mon, 30 Apr 2012 17:14:41 +1000
Subject: [PATCH] encoding/base64: don't ignore underlying souce read error in
decode
Fixes #3577
R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6137054
---
src/pkg/encoding/base64/base64.go | 2 +-
src/pkg/encoding/base64/base64_test.go | 49 ++++++++++++++++++++++++++
2 files changed, 50 insertions(+), 1 deletion(-)
diff --git a/src/pkg/encoding/base64/base64.go b/src/pkg/encoding/base64/base64.go
index f8a51a4e75..0b842f0661 100644
--- a/src/pkg/encoding/base64/base64.go
+++ b/src/pkg/encoding/base64/base64.go
@@ -318,7 +318,7 @@ func (d *decoder) Read(p []byte) (n int, err error) {
}
nn, d.err = io.ReadAtLeast(d.r, d.buf[d.nbuf:nn], 4-d.nbuf)
d.nbuf += nn
- if d.nbuf < 4 {
+ if d.err != nil || d.nbuf < 4 {
return 0, d.err
}
diff --git a/src/pkg/encoding/base64/base64_test.go b/src/pkg/encoding/base64/base64_test.go
index 9c35372598..f9b863c364 100644
--- a/src/pkg/encoding/base64/base64_test.go
+++ b/src/pkg/encoding/base64/base64_test.go
@@ -6,9 +6,11 @@ package base64
import (
"bytes"
+ "errors"
"io"
"io/ioutil"
"testing"
+ "time"
)
type testpair struct {
@@ -226,3 +228,50 @@ func TestNewLineCharacters(t *testing.T) {
}
}
}
+
+type nextRead struct {
+ n int // bytes to return
+ err error // error to return
+}
+
+// faultInjectReader returns data from source, rate-limited
+// and with the errors as written to nextc.
+type faultInjectReader struct {
+ source string
+ nextc <-chan nextRead
+}
+
+func (r *faultInjectReader) Read(p []byte) (int, error) {
+ nr := <-r.nextc
+ if len(p) > nr.n {
+ p = p[:nr.n]
+ }
+ n := copy(p, r.source)
+ r.source = r.source[n:]
+ return n, nr.err
+}
+
+// tests that we don't ignore errors from our underlying reader
+func TestDecoderIssue3577(t *testing.T) {
+ next := make(chan nextRead, 10)
+ wantErr := errors.New("my error")
+ next <- nextRead{5, nil}
+ next <- nextRead{10, wantErr}
+ d := NewDecoder(StdEncoding, &faultInjectReader{
+ source: "VHdhcyBicmlsbGlnLCBhbmQgdGhlIHNsaXRoeSB0b3Zlcw==", // twas brillig...
+ nextc: next,
+ })
+ errc := make(chan error)
+ go func() {
+ _, err := ioutil.ReadAll(d)
+ errc <- err
+ }()
+ select {
+ case err := <-errc:
+ if err != wantErr {
+ t.Errorf("got error %v; want %v", err, wantErr)
+ }
+ case <-time.After(5 * time.Second):
+ t.Errorf("timeout; Decoder blocked without returning an error")
+ }
+}
--
2.30.9