File gets silently truncated on upload

[seteq]

I tried to upload the Homie project's ui_bundle.gz file (49414 bytes) to a ESP-01 module (using the generic 512/64k setting).

The file gets truncated on upload and shows a file size of 45312 bytes on the SPI filesystem.
I suspect that is because the SPIFFS internals eat up the rest of the space.

Can you please check that and maybe display an error message?