... that will be used if an icon can't be found in the
current theme.
The Icon Theme Specification
https://standards.freedesktop.org/icon-theme-spec/latest/ar01s05.html
states that unthemed icons must be searched in the base directories,
i.e. /usr/share/icons, ... But in practice unthemed icons are
installed into /usr/share/pixmaps and this dir is not used as
a base dir for icon themes. So it's better to explicitly specify
fallback dirs to avoid needless access to the filesystem.
Also some KDE application install their own unthemed icons
(into /usr/share/<appname>/pics), that can't be found by
QIconLoader. With this change it would be possible for them
to specify dirs with unthemed icons and thus be displayed
correctly in non-KDE environments.
[ChangeLog][QtGui][QIcon] Added fallbackSearchPaths() that
will be used to find icons missing in the current icon theme.
Change-Id: I0dc55ba958b29356a3b0a2123d6b8faa24d4c91e
Task-number: QTBUG-33123
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>
85aa0fd041