rfc822: properly parse address lists

h.Text() parses blobs of encoded text without taking into account
specific handling for email addresses. h.AddressList(key) uses
mail.ParseAddressList(h.Get(key)) already deals with charsets and
quoted-printable stuff. Pass it the raw header value.

In some cases, mail.ParseAddressList will return a list of addresses
*and* an UnknownCharset error. In this specific case, ignore the error.

Fixes: https://todo.sr.ht/~rjarry/aerc/257
Reported-by: Inwit <[email protected]>
Signed-off-by: Robin Jarry <[email protected]>
Tested-by: Inwit <[email protected]>
Reviewed-by: Tristan Partin <[email protected]>

lib/rfc822/message.go

@@ -277,18 +277,15 @@ func parseReceivedHeader(h *mail.Header) (time.Time, error) {
 }
 
 func parseAddressList(h *mail.Header, key string) ([]*mail.Address, error) {
-	hdr, err := h.Text(key)
-	if err != nil && !message.IsUnknownCharset(err) {
+	addrs, err := h.AddressList(key)
+	if len(addrs) == 0 {
+		// Only consider the error if the returned address list is empty
+		// Sometimes, we get a list of addresses and unknown charset
+		// errors which are not fatal.
 		return nil, err
 	}
-	if hdr == "" {
-		return nil, nil
-	}
-	add, err := mail.ParseAddressList(hdr)
-	if err != nil {
-		return []*mail.Address{{Name: hdr}}, nil
-	}
-	return add, err
+	// If we got at least one address, ignore any returned error.
+	return addrs, nil
 }
 
 // RawMessage is an interface that describes a raw message