Description of problem:
I just tried to launch ZIM and it crashed.

Version-Release number of selected component:
Zim-0.73.5-1.fc34

Additional info:
reporter:       libreport-2.15.2
backtrace_rating: 4
cgroup:         0::/user.slice/user-1000.slice/session-2.scope
cmdline:        /usr/bin/python3 /usr/bin/zim
crash_function: draw_strikethrough
executable:     /usr/bin/python3.9
journald_cursor: s=be082c7b84d44e54aa950fddda3256dd;i=122794;b=cab6a3c2bae743b8895b7826f5f6e927;m=4320c5635;t=5ca36bf10a686;x=1a6d7a63ec274dae
kernel:         5.13.12-200.fc34.x86_64
rootdir:        /
runlevel:       N 5
type:           CCpp
uid:            1000

Truncated backtrace:
Thread no. 1 (10 frames)
 #0 draw_strikethrough at ../pango/pango-renderer.c:288
 #1 handle_line_state_change at ../pango/pango-renderer.c:341
 #2 pango_renderer_part_changed at ../pango/pango-renderer.c:1440
 #3 pango_renderer_set_alpha at ../pango/pango-renderer.c:1381
 #4 pango_renderer_default_prepare_run at ../pango/pango-renderer.c:1550
 #5 gtk_text_renderer_prepare_run at /usr/src/debug/gtk3-3.24.30-1.fc34.x86_64/gtk/gtktextdisplay.c:182
 #6 pango_renderer_prepare_run at ../pango/pango-renderer.c:1461
 #7 pango_renderer_draw_layout_line at ../pango/pango-renderer.c:620
 #8 render_para at /usr/src/debug/gtk3-3.24.30-1.fc34.x86_64/gtk/gtktextdisplay.c:705
 #9 gtk_text_layout_draw at /usr/src/debug/gtk3-3.24.30-1.fc34.x86_64/gtk/gtktextdisplay.c:942