bufio: fix bug that ReadFrom stops before EOF or error
ReadFrom should not return until it receives a non-nil error
or too many contiguous (0, nil)s from a given reader.
Currently it immediately returns if it receives one (0, nil).
Fixes #7611.
LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/76400048
diff --git a/src/pkg/bufio/bufio.go b/src/pkg/bufio/bufio.go
index ef74471..de81b4d 100644
--- a/src/pkg/bufio/bufio.go
+++ b/src/pkg/bufio/bufio.go
@@ -38,6 +38,7 @@
}
const minReadBufferSize = 16
+const maxConsecutiveEmptyReads = 100
// NewReaderSize returns a new Reader whose buffer has at least the specified
// size. If the argument io.Reader is already a Reader with large enough
@@ -625,9 +626,16 @@
return n, err1
}
}
- m, err = r.Read(b.buf[b.n:])
- if m == 0 {
- break
+ nr := 0
+ for nr < maxConsecutiveEmptyReads {
+ m, err = r.Read(b.buf[b.n:])
+ if m != 0 || err != nil {
+ break
+ }
+ nr++
+ }
+ if nr == maxConsecutiveEmptyReads {
+ return n, io.ErrNoProgress
}
b.n += m
n += int64(m)
