Fix mg_sntp_parse()

test/fuzz.c

@@ -4,25 +4,32 @@
 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
   struct mg_dns_message dm;
   mg_dns_parse(data, size, &dm);
+  mg_dns_parse(NULL, 0, &dm);
 
   struct mg_http_message hm;
   mg_http_parse((const char *) data, size, &hm);
+  mg_http_parse(NULL, 0, &hm);
 
   struct mg_str body = mg_str_n((const char *) data, size);
   char tmp[256];
   mg_http_get_var(&body, "key", tmp, sizeof(tmp));
   mg_url_decode((char *) data, size, tmp, sizeof(tmp), 1);
   mg_url_decode((char *) data, size, tmp, 1, 1);
+  mg_url_decode(NULL, 0, tmp, 1, 1);
 
   struct mg_mqtt_message mm;
   mg_mqtt_parse(data, size, &mm);
+  mg_mqtt_parse(NULL, 0, &mm);
 
   struct timeval tv;
   mg_sntp_parse(data, size, &tv);
+  mg_sntp_parse(NULL, 0, &tv);
 
   char buf[size * 4 / 3 + 5];  // At least 4 chars and nul termination
   mg_base64_decode((char *) data, size, buf);
+  mg_base64_decode(NULL, 0, buf);
   mg_base64_encode(data, size, buf);
+  mg_base64_encode(NULL, 0, buf);
 
   return 0;
 }

test/unit_test.c

@@ -247,6 +247,8 @@ static void test_sntp(void) {
     ASSERT(tm->tm_sec == 21);
     ASSERT(mg_sntp_parse(bad_good, sizeof(bad_good), &tv) == -1);
   }
+
+  ASSERT(mg_sntp_parse(NULL, 0, &tv) == -1);
 }
 
 static void mqtt_cb(struct mg_connection *c, int ev, void *evd, void *fnd) {
@@ -860,6 +862,11 @@ static void test_str(void) {
   ASSERT(mg_strcmp(mg_str("hi"), mg_strstrip(mg_str(" \thi\r\n"))) == 0);
 }
 
+static void test_dns(void) {
+  struct mg_dns_message dm;
+  ASSERT(mg_dns_parse(NULL, 0, &dm) == 0);
+}
+
 static void test_util(void) {
   char buf[100], *s = mg_hexdump("abc", 3);
   ASSERT(s != NULL);
@@ -876,6 +883,8 @@ static void test_util(void) {
 int main(void) {
   mg_log_set("3");
   test_util();
+  test_sntp();
+  test_dns();
   test_mqtt();
   test_str();
   test_timer();
@@ -893,7 +902,6 @@ int main(void) {
   test_http_client();
   test_http_no_content_length();
   test_http_pipeline();
-  test_sntp();
   printf("SUCCESS. Total tests: %d\n", s_num_tests);
   return EXIT_SUCCESS;
 }