Crash report: https://crash-stats.mozilla.org/report/index/6ecaa5fb-cb0e-4d95-bced-b6e340200908

Top 10 frames of crashing thread:

0 libglib-2.0.so.0 g_sequence_iter_get_sequence ../../../glib/gsequence.c:1187
1 libgtk-3.so.0 iter_is_valid ./debian/build/deb/gtk/../../../../gtk/gtkliststore.c:389
2 libgtk-3.so.0 gtk_list_store_set_valist ./debian/build/deb/gtk/../../../../gtk/gtkliststore.c:1133
3 libgtk-3.so.0 gtk_list_store_set ./debian/build/deb/gtk/../../../../gtk/gtkliststore.c:1179
4 libgtk-3.so.0 disconnect_printer_details_request ./debian/build/deb/gtk/../../../../gtk/gtkprintunixdialog.c:864
5 libgtk-3.so.0 selected_printer_changed ./debian/build/deb/gtk/../../../../gtk/gtkprintunixdialog.c:2034
6 libgobject-2.0.so.0 _g_closure_invoke_va ../../../gobject/gclosure.c:873
7 libgobject-2.0.so.0 g_signal_emit_valist ../../../gobject/gsignal.c:3407
8 libgobject-2.0.so.0 <name omitted> ../../../gobject/gsignal.c:3554
9 libgtk-3.so.0 gtk_tree_view_real_set_cursor ./debian/build/deb/gtk/../../../../gtk/gtktreeview.c:13347

Affected versions

• 81.0b7 (BuildId:20200906164749)

Affected platforms

• Ubuntu 20.04 64bit.

Additional notes

• This was a one time crash, I was unable to reproduce it in many other attempts.
• The printer in cause is a HP MFP M28a.
• The steps I've used when running into this were the following:

Steps to reproduce

1. Open Firefox.
2. Navigate to any page and open up the Print menu.
3. Disconnect the printer.

Expected result

• Printer is no longer displayed on the available printers list.

Actual result

• Browser crashed.

Regression Window

• Not sure if this is a regression or not since I've only ran into it once so far.

[Suggested Severity]

• S4

We've not seen an increase in crashes since b7 (pref off) went out, so marking this P3 for now.

Some additional information that could help:

I've notice that this crash happens when trying to print after the printer was turned on and the "Getting printer information" is displayed on print selection screen (after the printer was selected).
Also, it helps to make a Selection (i.e. select to print only page 2) and then unplug the printer from the usb, without clicking print.

Ran twice today into this crash on Fx 81.0b8.

https://crash-stats.mozilla.org/report/index/d36184d5-119b-40c5-8c02-ce6bd0200909
https://crash-stats.mozilla.org/report/index/d31aa315-3bcf-43ee-96ae-286610200909

Feels like a core bug. Maybe for v81, maybe for v82?

The product::component has been changed since the backlog priority was decided, so we're resetting it.
For more information, please visit auto_nag documentation.

Given the very specific and unusual steps needed to reproduce, and that all three crash reports for Beta have come from Cornel, I don't think we need to try to fix this in v81. Additionally, since there are crashes with this stack going back as far as the crash graph goes, I don't think this even a new or worsened crash.

Closing because no crashes reported for 12 weeks.