pavucontrol segfaults when closing with [CTRL]+[q]

[Jakob Lell]

When closing pavucontrol with the [CTRL]+[q] keyboard shortcut, it directly segfaults. The problem affects both Ubuntu 20.04 (pavucontrol 4.0-1build1) and 20.10 (pavucontrol 4.0-2) and can easily be reproduced (tried it on two different machines and also in a VM).

From the crash dump (also uploaded one via the crash reporting dialog, don't know if anyone is actively analyzing crash uploads for universe packages there):

$ cat Stacktrace
#0 0x00007f408d4822c5 in Gtk::Main::quit() () at /usr/lib/x86_64-linux-gnu/libgtkmm-3.0.so.1
#1 0x000056074fb58204 in ()
#2 0x00007f408d4ebfe9 in Gtk::Widget_Class::key_press_event_callback(_GtkWidget*, _GdkEventKey*) () at /usr/lib/x86_64-linux-gnu/libgtkmm-3.0.so.1
#3 0x00007f408c9fa7ec in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#4 0x00007f408c5b1b56 in () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#5 0x00007f408c5c9f09 in g_signal_emit_valist () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#6 0x00007f408c5cada3 in g_signal_emit () at /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
#7 0x00007f408c9a3514 in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#8 0x00007f408c851e0f in () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#9 0x00007f408c853a93 in gtk_main_do_event () at /usr/lib/x86_64-linux-gnu/libgtk-3.so.0
#10 0x00007f408befde89 in () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#11 0x00007f408bf328e6 in () at /usr/lib/x86_64-linux-gnu/libgdk-3.so.0
#12 0x00007f408c4be4db in g_main_context_dispatch () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#13 0x00007f408c4be788 in () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#14 0x00007f408c4be853 in g_main_context_iteration () at /usr/lib/x86_64-linux-gnu/libglib-2.0.so.0
#15 0x00007f408bc1f54d in g_application_run () at /usr/lib/x86_64-linux-gnu/libgio-2.0.so.0
#16 0x000056074fb45579 in main ()

$ cat SegvAnalysis |c++filt
Segfault happened at: 0x7f408d4822c5 <Gtk::Main::quit()+21>: mov (%rdi),%rax
PC (0x7f408d4822c5) ok
source "(%rdi)" (0x00000000) not located in a known VMA region (needed readable region)!
destination "%rax" ok

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.