diff --git a/src/pkg/bufio/bufio.go b/src/pkg/bufio/bufio.go
index 497e770fb15..cb2667b2832 100644
--- a/src/pkg/bufio/bufio.go
+++ b/src/pkg/bufio/bufio.go
@@ -103,6 +103,12 @@ func (b *Reader) fill() {
 	}
 }
 
+func (b *Reader) readErr() os.Error {
+	err := b.err
+	b.err = nil
+	return err
+}
+
 // Peek returns the next n bytes without advancing the reader. The bytes stop
 // being valid at the next read call. If Peek returns fewer than n bytes, it
 // also returns an error explaining why the read is short. The error is
@@ -121,7 +127,7 @@ func (b *Reader) Peek(n int) ([]byte, os.Error) {
 	if m > n {
 		m = n
 	}
-	err := b.err
+	err := b.readErr()
 	if m < n && err == nil {
 		err = ErrBufferFull
 	}
@@ -136,11 +142,11 @@ func (b *Reader) Peek(n int) ([]byte, os.Error) {
 func (b *Reader) Read(p []byte) (n int, err os.Error) {
 	n = len(p)
 	if n == 0 {
-		return 0, b.err
+		return 0, b.readErr()
 	}
 	if b.w == b.r {
 		if b.err != nil {
-			return 0, b.err
+			return 0, b.readErr()
 		}
 		if len(p) >= len(b.buf) {
 			// Large read, empty buffer.
@@ -150,11 +156,11 @@ func (b *Reader) Read(p []byte) (n int, err os.Error) {
 				b.lastByte = int(p[n-1])
 				b.lastRuneSize = -1
 			}
-			return n, b.err
+			return n, b.readErr()
 		}
 		b.fill()
 		if b.w == b.r {
-			return 0, b.err
+			return 0, b.readErr()
 		}
 	}
 
@@ -174,7 +180,7 @@ func (b *Reader) ReadByte() (c byte, err os.Error) {
 	b.lastRuneSize = -1
 	for b.w == b.r {
 		if b.err != nil {
-			return 0, b.err
+			return 0, b.readErr()
 		}
 		b.fill()
 	}
@@ -210,7 +216,7 @@ func (b *Reader) ReadRune() (rune int, size int, err os.Error) {
 	}
 	b.lastRuneSize = -1
 	if b.r == b.w {
-		return 0, 0, b.err
+		return 0, 0, b.readErr()
 	}
 	rune, size = int(b.buf[b.r]), 1
 	if rune >= 0x80 {
@@ -262,7 +268,7 @@ func (b *Reader) ReadSlice(delim byte) (line []byte, err os.Error) {
 		if b.err != nil {
 			line := b.buf[b.r:b.w]
 			b.r = b.w
-			return line, b.err
+			return line, b.readErr()
 		}
 
 		n := b.Buffered()
diff --git a/src/pkg/bufio/bufio_test.go b/src/pkg/bufio/bufio_test.go
index 123adac29a4..5709213c839 100644
--- a/src/pkg/bufio/bufio_test.go
+++ b/src/pkg/bufio/bufio_test.go
@@ -53,11 +53,12 @@ func readBytes(buf *Reader) string {
 		if e == os.EOF {
 			break
 		}
-		if e != nil {
+		if e == nil {
+			b[nb] = c
+			nb++
+		} else if e != iotest.ErrTimeout {
 			panic("Data: " + e.String())
 		}
-		b[nb] = c
-		nb++
 	}
 	return string(b[0:nb])
 }
@@ -86,6 +87,7 @@ var readMakers = []readMaker{
 	{"byte", iotest.OneByteReader},
 	{"half", iotest.HalfReader},
 	{"data+err", iotest.DataErrReader},
+	{"timeout", iotest.TimeoutReader},
 }
 
 // Call ReadString (which ends up calling everything else)
@@ -97,7 +99,7 @@ func readLines(b *Reader) string {
 		if e == os.EOF {
 			break
 		}
-		if e != nil {
+		if e != nil && e != iotest.ErrTimeout {
 			panic("GetLines: " + e.String())
 		}
 		s += s1
diff --git a/src/pkg/testing/iotest/reader.go b/src/pkg/testing/iotest/reader.go
index e4003d74450..daa6ede08e6 100644
--- a/src/pkg/testing/iotest/reader.go
+++ b/src/pkg/testing/iotest/reader.go
@@ -58,7 +58,7 @@ func (r *dataErrReader) Read(p []byte) (n int, err os.Error) {
 			r.unread = r.data[0:n1]
 			err = err1
 		}
-		if n > 0 {
+		if n > 0 || err != nil {
 			break
 		}
 		n = copy(p, r.unread)
@@ -66,3 +66,22 @@ func (r *dataErrReader) Read(p []byte) (n int, err os.Error) {
 	}
 	return
 }
+
+var ErrTimeout = os.NewError("timeout")
+
+// TimeoutReader returns ErrTimeout on the second read
+// with no data.  Subsequent calls to read succeed.
+func TimeoutReader(r io.Reader) io.Reader { return &timeoutReader{r, 0} }
+
+type timeoutReader struct {
+	r     io.Reader
+	count int
+}
+
+func (r *timeoutReader) Read(p []byte) (int, os.Error) {
+	r.count++
+	if r.count == 2 {
+		return 0, ErrTimeout
+	}
+	return r.r.Read(p)
+}