lib-mail: parse_mailbox: Set display name instead mailbox when parsin…

…g failed

It does not make sense to set mailbox without domain on incorrect input.
Rather set display name which is more likely useable value.

Test case:

  test

is parsed as:

  { name = "test", mailbox = NULL, domain = NULL }

src/lib-mail/message-address.c

@@ -205,6 +205,11 @@ static int parse_mailbox(struct message_address_parser_context *ctx)
 		/* nope, should be addr-spec */
 		ctx->parser.data = start;
 		ret = parse_addr_spec(ctx);
+		if (ctx->addr.invalid_syntax && ctx->addr.name == NULL &&
+		    ctx->addr.mailbox == NULL && ctx->addr.domain == NULL) {
+			ctx->addr.name = ctx->addr.mailbox;
+			ctx->addr.mailbox = NULL;
+		}
 	}
 
 	if (ret < 0)