Comment # 2 on bug 1022830 from Guillaume Lang

(In reply to Wolfgang Rosenauer from comment #1)
[..]
> From what I read it seems to be a Gtk(3) decision to ignore X dpi settings?
[..]
> To compare with other Gtk3 based applications probably use evince (because I
> know offhand that this is Gtk3 (while for example I think gimp is not yet).
> Please compare the font sizes and mouse cursors.

Indeed, this appears GTK-related: Evince uses a tiny font size, consistent with
that used by Firefox.

However:
- Cursor inside the window:
  Evince = KDE cursor as long as no specific area (such as frame resizing)
imposes a change in cursor.
  Firefox = not KDE
- Cursor on a window corner:
  Evince = not KDE
  Firefox = KDE cursor
- Main window title bar:
  Evince = tiny (height, window title, icons)
  Firefox = normal
  Strangely enough, Evince's 'About' window has a title bar of normal size.


PARTIAL WORK-AROUND
In '~/.Xresources':
Xft.dpi:    192

=> font size: ok for Firefox and Evince.
=> Evince title bar: normal height, normal window title, but still tiny icons
including the minimize/maximize/close icons.
=> no changes for the cursor situation (unsurprisingly).