Waybar: wlr/taskbar: polkit-gnome-authentication-agent-1 window crashes waybar

[cryptoluks]

Hi,

if wlr/taskbar is active in waybar config, the dialog from polkit-gnome-authentication-agent-1 crashes waybar. Even with waybar --log-level trace there can only be the segfaul observed:

[2020-11-24 13:45:52.994] [debug] Task (7) user: systemctl daemon-reload [Mate-terminal] <AMif> changed
[1]    9186 segmentation fault (core dumped)  waybar --log-level trace

The dialog can be triggered with for example running systemctl daemon-reload as a user.

When removing wlr/taskbar from modules, no crash happens at all.

Thanks.

[clapbr]

Can confirm this.

[cryptoluks]

I captured a backtrace with gdb:

#0  0x00007ffff78a1cda in Gio::Icon::to_string[abi:cxx11]() const () at /usr/lib/libgiomm-2.4.so.1
#1  0x00005555555dc511 in  ()
#2  0x00005555555dd18b in  ()
#3  0x00005555555ddd12 in  ()
#4  0x00007ffff64b8acd in  () at /usr/lib/libffi.so.7
#5  0x00007ffff64b803a in  () at /usr/lib/libffi.so.7
#6  0x00007ffff7f96e92 in  () at /usr/lib/libwayland-client.so.0
#7  0x00007ffff7f936c1 in  () at /usr/lib/libwayland-client.so.0
#8  0x00007ffff7f94ccc in wl_display_dispatch_queue_pending () at /usr/lib/libwayland-client.so.0
#9  0x00007ffff6ecd475 in  () at /usr/lib/libgdk-3.so.0
#10 0x00007ffff6e9315b in gdk_display_get_event () at /usr/lib/libgdk-3.so.0
#11 0x00007ffff6ed2ca4 in  () at /usr/lib/libgdk-3.so.0
#12 0x00007ffff6b6c914 in g_main_context_dispatch () at /usr/lib/libglib-2.0.so.0
#13 0x00007ffff6bc07d1 in  () at /usr/lib/libglib-2.0.so.0
#14 0x00007ffff6b6b121 in g_main_context_iteration () at /usr/lib/libglib-2.0.so.0
#15 0x00007ffff6d72d1e in g_application_run () at /usr/lib/libgio-2.0.so.0
#16 0x000055555557fa3a in  ()
#17 0x000055555557ecac in main ()

So obviously no symbols are resolving for the waybar stuff, but at the to_string method of libgiomm library it seems to crash. This functions seems to be called in taskbar.cpp here:

https://github.com/Alexays/Waybar/blob/fd11711673a4b17fd69aaa198dbe483e72fb24bb/src/modules/wlr/taskbar.cpp#L99

[Alexays]

@cryptoluks Can yout test with latest commit (05b12602d4f1fde4c13309a0b3a70afb010d3231) on master?

[cryptoluks]

@cryptoluks Can yout test with latest commit (05b1260) on master?

Jup, with the nullptr check it works for me. No more crashing. Thanks for the fast fix!