[colord] Are display device IDs still unique if EDID contains no 'ASCII' serial?

[Florian Höch]

 From what I've seen so far, the device IDs for displays in colord's 
database end with the ASCII serial from EDID, or as fallback with the 
serial number from bytes 12...15 if the former isn't set (if the EDID is 
available at all).

I looked at the raw EDID of my screens, all from different 
manufacturers, and they all have the same serial at bytes 12...15 
(16843009, hex 01010101). Most of them except my Philips LCD TV have a 
unique non-generic monitor name and ASCII serial though.

I'm wondering if, in the case that there is no ASCII serial available 
from EDID and the monitor name is very generic, could it be possible to 
introduce duplicate device ID entries in colord's database if several of 
these devices are connected?

E.g. my Philips LCD TV has a very generic EDID monitor name of 'Philips 
FTV', no ASCII serial and the serial field (bytes 12...15) is 16843009 
(hex 01010101) as mentioned above.
The entry in colord's device list is 
'xrandr_Philips_Consumer_Electronics_Company_Philips_FTV_16843009', so 
basically I'm wondering what's going to happen if I e.g. had another 
Philips TV connected (but I only have the one, so I can't try it).
Has this been thought of?

Florian