Lots of IEEE 1284 Device IDs in the wrong case

[Tim Waugh]

Lots of IEEE 1284 Device IDs listed in the HPLIP PPD files have the MDL value entirely in lower case, but I don't think that's correct. I've never seen an HP printer device claim to have an MDL value entirely in lower case, and here's at least one example where it is definitely wrong:

https://bugzilla.redhat.com/show_bug.cgi?id=1194186#c4

This is the output from lpinfo -l -v, and the relevant part is here:

Device: uri = dnssd://HP%20LaserJet%20500%20color%20M551%20%5B176998%5D._ipp._tcp.local/?uuid=36e3198f-3e0f-11e3-a946-8f8861991f10
        class = network
        info = HP LaserJet 500 color M551 [176998]
        make-and-model = Hewlett-Packard HP LaserJet 500 color M551
        device-id = MFG:Hewlett-Packard;MDL:HP LaserJet 500 color M551;FZY:0;CMD:PDF,PS,PCL,URF;
        location =

The only change the dnssd backend makes to the IEEE 1284 Device ID when one exists is to set 'FZY:0;' to indicate that it is actually the ID it got from the device's DNS-SD TXT record.

Clearly, the MDL is "HP LaserJet 500 color M551", with capital H, P, J, and M. But the HPLIP,
hplip-3.15.2/prnt/ps/hp-laserjet_500_color_m551-ps.ppd, has:

*1284DeviceID: "MFG:Hewlett-Packard;MDL:hp laserjet 500 color m551;"

The MDL field is all in lower case.

The point of the IEEE 1284 Device ID is that it identifies the device uniquely. If the driver and the device say different things, it makes it hard to match them up.

As far as I can tell, this affects all the PPDs in prnt/ps. There are probably more instances as well.