[sane-devel] Strange behaviour by airscan

[Andrea Croci]

Hello,

using Ubuntu 18.04 with scanimage (sane-backends) 1.0.31-179-ge4ef0548b; 
backend version 1.0.31 (installed from ppa), I get:

scanimage -L
device `epson2:net:192.168.2.101' is a Epson PID 08B9 flatbed scanner
device `epkowa:net:192.168.2.101:1865' is a Epson WF-7610/7620 Series 
flatbed scanner
device `airscan:e2:Canon MF745C/746C' is a eSCL Canon MF745C/746C eSCL 
network scanner
device `airscan:w3:EPSON WF-7620 Series' is a WSD EPSON WF-7620 Series 
WSD network scanner

(notice "airscan:e2:..." Yet

scanimage --help -d 'airscan:e2:Canon MF745C/746C'
Usage: scanimage [OPTION]...

Start image acquisition on a scanner device and write image data to
standard output.

Parameters are separated by a blank from single-character options (e.g.
-d epson) and by a "=" from multi-character options (e.g. 
--device-name=epson).
-d, --device-name=DEVICE   use a given scanner device (e.g. hp:/dev/scanner)
     --format=pnm|tiff|png|jpeg  file format of output file
-i, --icc-profile=PROFILE  include this ICC profile into TIFF file
-L, --list-devices         show available scanner devices
-f, --formatted-device-list=FORMAT similar to -L, but the FORMAT of the 
output
                            can be specified: %d (device name), %v (vendor),
                            %m (model), %t (type), %i (index number), and
                            %n (newline)
-b, --batch[=FORMAT]       working in batch mode, FORMAT is `out%d.pnm' 
`out%d.tif'
                            `out%d.png' or `out%d.jpg' by default 
depending on --format
                            This option is incompatible with 
--output-file.    --batch-start=#        page number to start naming 
files with
     --batch-count=#        how many pages to scan in batch mode
     --batch-increment=#    increase page number in filename by #
     --batch-double         increment page number by two, same as
                            --batch-increment=2
     --batch-print          print image filenames to stdout
     --batch-prompt         ask for pressing a key before scanning a page
     --accept-md5-only      only accept authorization requests using md5
-p, --progress             print progress messages
-o, --output-file=PATH     save output to the given file instead of stdout.
                            This option is incompatible with --batch.
-n, --dont-scan            only set options, don't actually scan
-T, --test                 test backend thoroughly
-A, --all-options          list all available backend options
-h, --help                 display this help message and exit
-v, --verbose              give even more status messages
-B, --buffer-size=#        change input buffer size (in kB, default 32)
-V, --version              print version information
Output format is not set, using pnm as a default.
scanimage: open of device airscan:e2:Canon MF745C/746C failed: Invalid 
argument
Type ``scanimage --help -d DEVICE'' to get list of all options for DEVICE.

List of available devices:
     epson2:net:192.168.2.101 epkowa:net:192.168.2.101:1865
     airscan:e0:Canon MF745C/746C airscan:w3:EPSON WF-7620 Series

notice "airscan:e0:..."

Addressing the scanner as "airscan:e0:..." works great. Not a big 
problem, I just find it kind of funny.