lib-mail: message-address: Fix assert panic occurring in message_addr…

…ess_parse_path() when no opening `<' is found.

Panic was:

Panic: file message-address.c: line 147 (parse_angle_addr): assertion failed: (*ctx->parser.data == '<')

src/lib-mail/message-address.c

@@ -424,6 +424,8 @@ message_address_parse_path_real(pool_t pool, const unsigned char *data,
 
 	if (rfc822_skip_lwsp(&ctx.parser) <= 0)
 		return -1;
+	if (*ctx.parser.data != '<')
+		return -1;
 	if ((ret=parse_angle_addr(&ctx)) < 0 ||
 		(ctx.addr.mailbox != NULL && ctx.addr.domain == NULL)) {
 		ctx.addr.invalid_syntax = TRUE;

src/lib-mail/test-message-address.c

@@ -395,11 +395,39 @@ static void test_message_address_path(void)
 	test_end();
 }
 
+static void test_message_address_path_invalid(void)
+{
+	static const char *tests[] = {
+		">",
+		" > ",
+		"user@domain",
+		"  user@domain  ",
+		"user@domain>",
+		"  user@domain>  ",
+		"<user>",
+		"<@route@route2:user>",
+	};
+	const struct message_address *addr;
+	unsigned int i;
+
+	test_begin("message address path invalid");
+
+	for (i = 0; i < N_ELEMENTS(tests); i++) {
+		const char *test = tests[i];
+		int ret;
+
+		ret = test_parse_path(test, &addr);
+		test_assert_idx(ret < 0, i);
+	}
+	test_end();
+}
+
 int main(void)
 {
 	static void (*const test_functions[])(void) = {
 		test_message_address,
 		test_message_address_path,
+		test_message_address_path_invalid,
 		NULL
 	};
 	return test_run(test_functions);