Xpra: Ticket #732: make it easier to know what version of the dummy driver is installed (and if it has the required patches)

At the moment, the only way to tell is to check the package database (and assume it is the version in use..) or parse the server output and look for the tell-tale sign:

[245872.234] (II) DUMMY(0): get_constant_dpi_value() found property "dummy-constant-xdpi" with value=96
[245872.234] (II) DUMMY(0): get_constant_dpi_value() found property "dummy-constant-ydpi" with value=96
[245872.234] (II) DUMMY(0): mm(dpi 96x96)=677x423

Things like xvinfo and glxinfo don't help much either. I don't think we can get that information through the X11 randr protocol either. The only place where the driverName seems to be exported is in ProcDRI2Connect.

We should add a root window property (a bit like what Xvfb does) and stick the version and patch level in there. Then we can look it up on the server and know what we're dealing with, and emit a warning if it looks outdated.

Code would probably look like this:

	Atom prop = MakeAtom(pProp->name, strlen(pProp->name), TRUE);
	err = dixChangeWindowProperty(serverClient, pWin,
				prop, pProp->type, pProp->format, PropModeReplace,
                                pProp->size, pProp->data, FALSE);


Sat, 08 Nov 2014 07:44:27 GMT - Antoine Martin: owner, status, description changed


Fri, 03 Jul 2015 15:24:16 GMT - Antoine Martin:

Improvement in r9770: we warn if the DPI is way off.


Tue, 12 Jul 2016 16:51:50 GMT - Antoine Martin: milestone changed

Milestone renamed


Sun, 21 Aug 2016 09:55:49 GMT - Antoine Martin: milestone changed

Milestone renamed


Wed, 15 Feb 2017 10:01:31 GMT - Antoine Martin: status changed; resolution set

Best to work on #56 and get that solved.


Sat, 23 Jan 2021 05:04:21 GMT - migration script:

this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/732