From: Timmy Douglas <timmyd983@gmail.com>
Date: Sat, 1 Feb 2020 22:14:30 +0000 (+0000)
Subject: net/mail: skip empty entries in parseAddressList
X-Git-Tag: go1.15beta1~1159
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=30e3bf2051e1659ba7ea1d14849f79deb82a5606;p=gostls13.git

net/mail: skip empty entries in parseAddressList

RFC 5322 has a section 4.4 where it says that address-list could
have "null" members: "That is, there could be two or more commas in
such a list with nothing in between them, or commas at the beginning
or end of the list." This change handles such a case so that mail
clients using this method on actual email messages get a reasonable
return value when they parse email.

Fixes #36959

Change-Id: I3ca240969935067262e3d751d376a06db1fef2a2
GitHub-Last-Rev: b96a9f2c075dfd67c3ff7b8ae0c12e12035f0da0
GitHub-Pull-Request: golang/go#36966
Reviewed-on: https://go-review.googlesource.com/c/go/+/217377
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
---

diff --git a/src/net/mail/message.go b/src/net/mail/message.go
index 0781310ed3..6833cfaec1 100644
--- a/src/net/mail/message.go
+++ b/src/net/mail/message.go
@@ -274,6 +274,15 @@ func (p *addrParser) parseAddressList() ([]*Address, error) {
 	var list []*Address
 	for {
 		p.skipSpace()
+
+		// allow skipping empty entries (RFC5322 obs-addr-list)
+		if p.consume(',') {
+			continue
+		}
+		if p.empty() {
+			break
+		}
+
 		addrs, err := p.parseAddress(true)
 		if err != nil {
 			return nil, err
diff --git a/src/net/mail/message_test.go b/src/net/mail/message_test.go
index acab538e18..75db767547 100644
--- a/src/net/mail/message_test.go
+++ b/src/net/mail/message_test.go
@@ -431,6 +431,20 @@ func TestAddressParsing(t *testing.T) {
 				},
 			},
 		},
+		// RFC5322 4.4 obs-addr-list
+		{
+			` , joe@where.test,,John <jdoe@one.test>,`,
+			[]*Address{
+				{
+					Name:    "",
+					Address: "joe@where.test",
+				},
+				{
+					Name:    "John",
+					Address: "jdoe@one.test",
+				},
+			},
+		},
 		{
 			`Group1: <addr1@example.com>;, Group 2: addr2@example.com;, John <addr3@example.com>`,
 			[]*Address{