I found that inode/directory (which are folders) are defaulted to Gwenview after an update. And it remains the same even after an OS re-installation.
Even though this can be easily changed in system settings, it’s still weird that Gwenview is the default application for folders and GIMP is the default for images.
Moreover, I have found that /usr/share/applications/mimeapps.list is a link to /var/cache/gio-2.0/gnome-mimeapps.list. Is this the desired behavior that the default mime mapping has something to do with GNOME?
Known problem caused by a glib (not glibc) update, and already fixed.
But I don’t know if the fix is already in Tumbleweed, probably not…
http://lists.opensuse.org/opensuse-factory/2016-02/msg00491.html
http://lists.opensuse.org/opensuse-factory/2016-02/msg00474.html
http://bugzilla.opensuse.org/show_bug.cgi?id=966739