bufio: don't return errors from good Peeks
Fixes #3022
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5674060
diff --git a/src/pkg/bufio/bufio_test.go b/src/pkg/bufio/bufio_test.go
index 9aec61e..a43cbd2 100644
--- a/src/pkg/bufio/bufio_test.go
+++ b/src/pkg/bufio/bufio_test.go
@@ -539,6 +539,27 @@
if _, err := buf.Peek(1); err != io.EOF {
t.Fatalf("want EOF got %v", err)
}
+
+ // Test for issue 3022, not exposing a reader's error on a successful Peek.
+ buf = NewReaderSize(dataAndEOFReader("abcd"), 32)
+ if s, err := buf.Peek(2); string(s) != "ab" || err != nil {
+ t.Errorf(`Peek(2) on "abcd", EOF = %q, %v; want "ab", nil`, string(s), err)
+ }
+ if s, err := buf.Peek(4); string(s) != "abcd" || err != nil {
+ t.Errorf(`Peek(4) on "abcd", EOF = %q, %v; want "abcd", nil`, string(s), err)
+ }
+ if n, err := buf.Read(p[0:5]); string(p[0:n]) != "abcd" || err != nil {
+ t.Fatalf("Read after peek = %q, %v; want abcd, EOF", p[0:n], err)
+ }
+ if n, err := buf.Read(p[0:1]); string(p[0:n]) != "" || err != io.EOF {
+ t.Fatalf(`second Read after peek = %q, %v; want "", EOF`, p[0:n], err)
+ }
+}
+
+type dataAndEOFReader string
+
+func (r dataAndEOFReader) Read(p []byte) (int, error) {
+ return copy(p, r), io.EOF
}
func TestPeekThenUnreadRune(t *testing.T) {
