From: Brad Fitzpatrick <bradfitz@golang.org>
Date: Wed, 16 Apr 2014 02:40:00 +0000 (-0700)
Subject: crypto/tls: don't block on Read of zero bytes
X-Git-Tag: go1.3beta1~64
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=853c99ddb8dc25ca361f1efdd65a9b371cc39fcb;p=gostls13.git

crypto/tls: don't block on Read of zero bytes

Fixes #7775

LGTM=rsc
R=agl, rsc
CC=golang-codereviews
https://golang.org/cl/88340043
---

diff --git a/src/pkg/crypto/tls/conn.go b/src/pkg/crypto/tls/conn.go
index 000b23cbca..550bc7f8fe 100644
--- a/src/pkg/crypto/tls/conn.go
+++ b/src/pkg/crypto/tls/conn.go
@@ -884,6 +884,11 @@ func (c *Conn) Read(b []byte) (n int, err error) {
 	if err = c.Handshake(); err != nil {
 		return
 	}
+	if len(b) == 0 {
+		// Put this after Handshake, in case people were calling
+		// Read(nil) for the side effect of the Handshake.
+		return
+	}
 
 	c.in.Lock()
 	defer c.in.Unlock()