Image devices may return a FP_DEVICE_ERROR_NOT_SUPPORTED error once capture
is already started, in such case handle the error going in non imaging mode

A device may produce both prints with image data and not, so only do it
in the case the prints contains image data

g_cancellable_is_cancelled already handles properly null values

This one can be useful in scripts, e.g. for building fingerprint
dataset.

Benjamin Berg authored 4 years ago and Benjamin Berg committed 4 years ago

This is based on the patch and observation from Bastien that some
URU4000B devices do not use encryption by default (it is a configuration
stored within the firmware). As such, it makes sense to always detect
whether encryption is in use by inspecting the image.

The encryption option would disable flipping of the image for the
URU400B device. Retain this behaviour for backward compatibility.

The value was set after the transfer was submitting, causing the value
to always be zero.

The user data for write_regs_cb needs to be set to wrdata. This was
simply missing, add the appropriate argument.