net: turn off dns compression for go resolver queries

We don't need compression enabled here, because we only set one question in the dns message. So there is nothing to compress. Also it reduces 8 allocs per LookupHost.

Change-Id: I0968f837011daf6d7a7b22d9af4a8cc5b2878f4c
GitHub-Last-Rev: 7eb3362bcaa86f47c9d975375b54c7177e8dd15e
GitHub-Pull-Request: golang/go#54576
Reviewed-on: https://go-review.googlesource.com/c/go/+/425043
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>

diff --git a/src/net/dnsclient_unix.go b/src/net/dnsclient_unix.go
index cc0bf244eab34cd84682b6ca901ae61e9b10ba1f..bf522e6b2869ebf60329c4e659e9a2ba0722f441 100644 (file)
--- a/src/net/dnsclient_unix.go
+++ b/src/net/dnsclient_unix.go
@@ -54,7 +54,6 @@ var (
 func newRequest(q dnsmessage.Question) (id uint16, udpReq, tcpReq []byte, err error) {
        id = uint16(randInt())
        b := dnsmessage.NewBuilder(make([]byte, 2, 514), dnsmessage.Header{ID: id, RecursionDesired: true})
-       b.EnableCompression()
        if err := b.StartQuestions(); err != nil {
                return 0, nil, nil, err
        }