Crash on close with Unicode dialog open and undocked

Steps to reproduce:

• open Inkscape
• open Unicode Dialog
• undock dialog
• close Inkscape (using top right X close button)

What happened?

• Crash
• Backtrace: inkscape-backtrace-on-close-undocked.txt

Emergency save activated!
Emergency save completed. Inkscape will close now.
If you can reproduce this crash, please file a bug at https://inkscape.org/report
with a detailed description of the steps leading to the crash, so we can fix it.
**
Gtk:ERROR:../../../../gtk/gtkwidget.c:5871:gtk_widget_get_frame_clock: assertion failed: (window != NULL)
Bail out! Gtk:ERROR:../../../../gtk/gtkwidget.c:5871:gtk_widget_get_frame_clock: assertion failed: (window != NULL)

What should have happened?

• No crash

Sample attachments:

Version Info:

• Inkscape 1.1-dev (fd6b5c62, 2021-01-11) Linux Mint 20
• bisection on appimages points to GDL replacement, also not replicated Inkscape 1.1-dev (ad8effaa, 2020-11-17)

Not replicated in Inkscape 1.0.1 (179fe947, 2021-01-06) (takes some time to close though) or Inkscape 0.92.5 (0ad1ac96, 2020-08-06) Linux Mint 20

No duplicates searching for crash Unicode and crash glyphs on Gitlab