net/mail: fix wrong error message in consumePhrase

Fixes #19415

Change-Id: I6414f82e42bd09f1793156befce326aeac919ea2
Reviewed-on: https://go-review.googlesource.com/37911Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/net/mail/message.go

@@ -393,7 +393,7 @@ func (p *addrParser) consumePhrase() (phrase string, err error) {
 		var word string
 		p.skipSpace()
 		if p.empty() {
-			return "", errors.New("mail: missing phrase")
+			break
 		}
 		isEncoded := false
 		if p.peek() == '"' {

src/net/mail/message_test.go

@@ -136,6 +136,7 @@ func TestAddressParsingError(t *testing.T) {
 		4: {"\"\\" + string([]byte{0x80}) + "\" <escaped-invalid-unicode@example.net>", "invalid utf-8 in quoted-string"},
 		5: {"\"\x00\" <null@example.net>", "bad character in quoted-string"},
 		6: {"\"\\\x00\" <escaped-null@example.net>", "bad character in quoted-string"},
+		7: {"John Doe", "no angle-addr"},
 	}
 
 	for i, tc := range mustErrTestCases {