Crash closing document (display units changed via Document Properties dialog)

Steps to reproduce:

• open Inkscape
• open document properties dialog
• change display units to inches
• close document properties dialog (required!)
• close document (ctrl+w not ctrl+q)

What happened?

crash, truncated backtrace below, backtrace: inkscape_backtrace_doc_properties_close.txt

Thread 1 "inkscape" received signal SIGSEGV, Segmentation fault.
SPDesktop::getNamedView (this=this@entry=0x0) at ../src/desktop.cpp:474
474		return namedview;
(gdb) bt
#0  0x00007ffff71d84b0 in SPDesktop::getNamedView() const (this=this@entry=0x0) at ../src/desktop.cpp:474
#1  0x00007ffff6e8b41c in Inkscape::UI::Dialog::DocumentProperties::update() (this=this@entry=0x555558c979a0) at ../src/ui/dialog/document-properties.cpp:1371
#2  0x00007ffff6e8b9a9 in Inkscape::UI::Dialog::DocumentProperties::_handleDocumentReplaced(SPDesktop*, SPDocument*) (this=0x555558c979a0, desktop=<optimised out>, document=0x5555565a6800) at ../src/ui/dialog/document-properties.cpp:1508

Inkscape Version and Operating System:

• Occurs in Inkscape 1.1-dev (efef7d6c, 2020-02-20) appimage and Inkscape 1.1-dev (8e914f5a, 2020-02-20) debug build
• Doesn't occur in Inkscape 1.1-dev (47466bfc, 2020-02-08) appimage (or alpha0, beta1 or beta2 release appimages)

Update: bisection ends in

commit d977fb1001f310ede5d60239955a898e18c5650d
Author: Thomas Holder <thomas@thomas-holder.de>
Date:   Sun Jan 12 19:48:33 2020 +0100

    Hidden dialogs stop receiving desktop signals
    
    Use map/unmap signals to connect and disconnect the desktop.

Tested Linux Mint 19.1