There is a crash in convert_xfce_output_info where it dereferences a NULL pointer when an external monitor is plugged in. The code is: 1592 static XfceOutputInfo *convert_xfce_output_info (gint output_id) 1593 { 1594 XfceOutputInfo *output; 1595 const XfceRRMode *mode, *preferred; 1596 RRMode preferred_mode; 1597 gint x, y; 1598 1599 xfce_randr_get_positions(xfce_randr, output_id, &x, &y); 1600 mode = xfce_randr_find_mode_by_id (xfce_randr, output_id, xfce_randr->mode[output_id]); 1601 preferred_mode = xfce_randr_preferred_mode(xfce_randr, output_id); 1602 preferred = xfce_randr_find_mode_by_id (xfce_randr, output_id, preferred_mode); ^ here preferred == NULL 1603 output = g_new0 (XfceOutputInfo, 1); 1604 output->id = output_id; 1605 output->x = x; 1606 output->y = y; 1607 output->user_data = NULL; 1608 output->display_name = xfce_randr->friendly_name[output_id]; 1609 output->connected = TRUE; 1610 output->on = xfce_randr->mode[output_id] != None; 1611 output->pref_width = preferred->width; ^ crash happens here There's a bit more detail including a reproducer in the Fedora downstream bug report: https://bugzilla.redhat.com/show_bug.cgi?id=1317382#c4 https://bugzilla.redhat.com/show_bug.cgi?id=1317382#c5
I think https://bugzilla.xfce.org/show_bug.cgi?id=12350 could be in some way related to this one. They are certainly in very similar places in the code.
Hello, I have added a patch that should resolve this issue. Please see https://git.xfce.org/xfce/xfce4-settings/commit/?id=cd1ef4dc2a5323f130c31754a631caa228c9fd3b and let me know if this helps.