Hi,

This comes from a bug reported at Mageia bugzilla:

https://bugs.mageia.org/show_bug.cgi?id=4408

oxygen-gtk developer reviewed the issue and determined that it is a GTK bug and should be reported here (see comment #3): 

----------------------------
The guilty code is (in details):

        gchar** gtkSearchPath;
        int nElements(0);
        gtk_icon_theme_get_search_path( gtk_icon_theme_get_default(),
&gtkSearchPath, &nElements );
        for( int i=0; i<nElements; i++ ) { searchPath.insert( gtkSearchPath[i]
); }

So from the gtk method call, I was expecting, by construction, gtkSearchPath[i]
not to be Null (never), or else it means nElements is just not calculated
right. 
-----------------------------

This is the initial bug description, please read the Mageia bug report for further details and backtraces:

metacity ( => gnome-classic, not gnome-shell & mutter) segfaults in oxygen
theme.
If you look at the GDB trace, you see the theme engine tries to dereference a
pointer in the NULL page

Version-Release number of selected component (if applicable):
lib64oxygen-gtk-1.2.0-2.mga2

How reproducible:
always

Steps to Reproduce:
1. switch Gtk+ theme to oxygen with gnome-tweak-tool
2. logout
3. login, session displays "an error happened"
4. run gdb from a console to see the trace