Fuzz-test mg_http_var and base64

test/fuzz.c

@@ -8,11 +8,19 @@ int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
   struct mg_http_message hm;
   mg_http_parse((const char *) data, size, &hm);
 
+  struct mg_str body = mg_str_n((const char *) data, size);
+  char tmp[256];
+  mg_http_get_var(&body, "key", tmp, sizeof(tmp));
+
   struct mg_mqtt_message mm;
   mg_mqtt_parse(data, size, &mm);
 
   struct timeval tv;
   mg_sntp_parse(data, size, &tv);
 
+  char buf[size * 4 / 3 + 5];  // At least 4 chars and nul termination
+  mg_base64_decode((char *) data, size, buf);
+  mg_base64_encode(data, size, buf);
+
   return 0;
 }