[xml] how to tell if xmlSaveFormatFile did not save entire doc?

["Daithi O'Cuinn" <docuinn gmail com>]

Hi there,

I am using xmlSaveFormatFile to save documents to disk and have come
across the situation where docs are being truncated due to disk space
running out.
I want to be able to detect this condition, but I cannot see a way of
checking that the bytes written return code of the function is less
than the total document size. Can I find out what the expected size
was, or detect this failure by other means?

Thanks,
Daithi.