GNOME Bugzilla – Bug 632145
duplicate monitor ids lead to garbage characters in gnome-display-properties
Last modified: 2012-06-20 17:12:09 UTC
The bug has been opened on https://bugs.launchpad.net/ubuntu/+source/gnome-desktop/+bug/651731 "I routinely connect my laptop to an external monitor - an IBM 20" display connected via VGA. In earlier Ubuntu releases this worked fine, with the two monitors showing up as 'Laptop' and 'IBM 20"' (IIRC) in the gnome-display-properties window. In Karmic and Lucid, however, functionality is still fine, but the label on the external monitor is usually filled with garbage characters. Exactly what shows up varies, but it is usually a handful of unicode characters without proper glyphs, followed by '20"'. https://bugs.edge.launchpad.net/ubuntu/+source/gnome-desktop/+bug/651731/+attachment/1661620/+files/Xorg.0.log ... Ok. I don't have a /usr/share/hwdata/pnp.ids, but I do have a /usr/share/libgnome-desktop/pnp.ids, which seems to contain the data you describe. Removing one of the entries seems to do the trick: as soon as I removed the "IBM France" entry, the monitor showed up in the control panel as "IBM Brasil 20"". Something I didn't mentioned earlier is that while a string of garbage was the most common symptom before, a few garbage characters then "France" was also quite common which makes sense now I know the data is coming from this list. Nonetheless looks like there is a bug where multiple matching entries in the table causes the string to be mangled."
the issue happens when the pnp.ids file has 2 entries with the same code, which is the case with those: "IBM IBM Brasil IBM IBM France"
The same happened to me with this manufacturer which has two entries: ELO Elo TouchSystems Inc ELO Tyco Electronics
The code has changed from this: http://git.gnome.org/browse/gnome-desktop/tree/libgnome-desktop/display-name.c?h=gnome-3-0#n192 to this: http://git.gnome.org/browse/gnome-desktop/tree/libgnome-desktop/gnome-pnp-ids.c#n196 I've also added a test case to gnome-desktop, so you can verify that it's valgrind clean. commit 8503ae8e1b860c60ea744fdc7064d090fc6690e6 Author: Bastien Nocera <hadess@hadess.net> Date: Wed Jun 20 17:28:28 2012 +0100 pnp-ids: Add test program