Arduino core for ESP32 Wiki content

SDFS File::flush() and SD_MMC.flush() appears to do nothing

Issues #1293 and #1173

Both SDFS and SD_MMC implementations seems to have a bug that flush() doesn’t write data to the SD card.

Possible workaround mentioned by psykokwak-com

Edit file vfs_api.cpp and add fsync(fileno(_f)); after fflush(_f); in the void VFSFileImpl::flush()