openQA vs. Rawhide

[Kamil Paral]

> There's a neat GTK+ debugging thing called the GtkInspector which you
> can launch from any GTK+ 3 app with shift+ctrl+D. From that you can

Or Ctrl+Shift+I, if you find that easier to remember (I as inspector) :-)

> look at Properties then GtkSettings, and look at the gtk-xft-*
> settings. I noticed two significant differences between anaconda
> running from boot.iso or KDE live and anaconda running from Workstation
> live, both at 1024x768 in a VM. gtk-xft-hintstyle is 'medium' in
> Workstation but 'full' in boot.iso/KDE, and gtk-xft-dpi is 98304 in
> Workstation but 98401 in boot.iso/KDE. That value is a DPI multiplied
> by 1024; Workstation's is exactly 96 (98304/1024 = 96), boot.iso/KDE
> is...a little bit more than 96.
> 
> Basically we figured out that for some reason the defaults that should
> be set by /etc/X11/Xresources don't seem to actually be merged into X,
> in boot.iso and KDE live image at least. So GDK (part of GTK+) falls
> back on its internal defaults for hinting style and display resolution
> (DPI). Its default for hinting style, in the absence of any external
> indication, is 'hintfull', and its default for DPI is to actually
> calculate the 'correct' DPI for the display. It turns out that a KVM at
> 1024x768 reports its "monitor's" vertical size as 203mm; if you
> reproduce GDK's calculation with 768 pixels and 203mm:
> 
> 768 (pixel height) * 25.4 (inches to MM) / 203 (height in MM) * 1024
> (GDK's multiplication factor) ~= 98401 (actually a bit lower but it
> gets rounded to the nearest integer)
> 
> and that's where the weird 98401 value comes from.

What, that's a one hell of a debug story. Awesome job.