mate-panel crashes in panel_profile_load, system unusable

[bje]

Description: Ubuntu 22.04.1 LTS
Release: 22.04

Package versions: mate-panel 1.26.2-1
                  libcairo2:amd64 1.16.0-5ubuntu2

mate-panel crashes on a fresh Ubuntu 22.04.1 LTS system. It has the effect that the user gets a background image, can manually start applications with Alt+F2, but cannot see a menu or any desktop icons. Here is a backtrace obtained from trying to start mate-panel remotely under gdb:

Thread 1 "mate-panel" received signal SIGSEGV, Segmentation fault.
0x00007ffff74a71dc in cairo_surface_reference () from /lib/x86_64-linux-gnu/libcairo.so.2
(gdb) bt
#0 0x00007ffff74a71dc in cairo_surface_reference () from /lib/x86_64-linux-gnu/libcairo.so.2
#1 0x00005555555d0453 in ?? ()
#2 0x00005555555addcb in ?? ()
#3 0x00005555555adf3f in ?? ()
#4 0x00007ffff71c2d2f in g_closure_invoke () from /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#5 0x00007ffff71de7d5 in ?? () from /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#6 0x00007ffff71e0554 in g_signal_emit_valist () from /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#7 0x00007ffff71e07a3 in g_signal_emit () from /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#8 0x00007ffff7a911a2 in gtk_widget_size_allocate_with_baseline () from /lib/x86_64-linux-gnu/libgtk-3.so.0
#9 0x00005555555a358a in ?? ()
#10 0x00007ffff71e0640 in g_signal_emit_valist () from /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#11 0x00007ffff71e07a3 in g_signal_emit () from /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#12 0x00007ffff7aae2f3 in ?? () from /lib/x86_64-linux-gnu/libgtk-3.so.0
#13 0x00007ffff71c2d2f in g_closure_invoke () from /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#14 0x00007ffff71de7d5 in ?? () from /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#15 0x00007ffff71e0554 in g_signal_emit_valist () from /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#16 0x00007ffff71e07a3 in g_signal_emit () from /lib/x86_64-linux-gnu/libgobject-2.0.so.0
#17 0x00007ffff7a90656 in gtk_widget_show () from /lib/x86_64-linux-gnu/libgtk-3.so.0
#18 0x00005555555b876a in panel_profile_load ()
#19 0x000055555557cfb9 in main ()

[bje (bje)]

Through trial and error, I managed to determine that a file in the user's home directory (in ~/.config/gtk-3.0) was causing this crash. The file is gtk.css. I've attached that file to this bug report.

Removing the entire gtk-3.0 directory fixes this problem, but it would have been better for it to have not happened in the first place.