bytes.Buffer.UnreadByte() gets error check backward #1396
Description
by kwwaters:
What steps will reproduce the problem?
1. Try using bytes.Buffer.UnreadByte()
What is the expected output?
UnreadByte() unreads a byte when the last operation was a read.
What do you see instead?
UnreadByte() returns "UnreadByte: previous operation was not a read"
Which compiler are you using (5g, 6g, 8g, gccgo)?
6g
Which operating system are you using?
Linux 2.6.36-gentoo-r5
Which revision are you using? (hg identify)
8eeee945e358+ release/release.2011-01-06
I looked at the source for tip and it appears to be broken as well, but I didn't try it.
Please provide any additional information below.
I think this patch fixes the test.
diff -r 47bc23fc4855 src/pkg/bytes/buffer.go
--- a/src/pkg/bytes/buffer.go Fri Jan 07 15:33:00 2011 +1100
+++ b/src/pkg/bytes/buffer.go Thu Jan 06 23:07:32 2011 -0800
@@ -291,7 +291,7 @@
// read operation. If write has happened since the last read, UnreadByte
// returns an error.
func (b *Buffer) UnreadByte() os.Error {
- if b.lastRead == opReadRune || b.lastRead == opRead {
+ if b.lastRead != opReadRune && b.lastRead != opRead {
return os.ErrorString("bytes.Buffer: UnreadByte: previous operation was not a read")
}
b.lastRead = opInvalid