State file not saved after printer deletion or on shutdown

[tillkamppeter]

Describe the bug I have the PostScript Printer Application running with several printers defined. I delete one of them (in this example "xxx") via the appropriate button in the web interface, also click the button on the page for confirming the deletion. On the main page of the web interface I see that the printer is removed. After that I shut down the Printer Application. When starting the Printer Application again the deleted printer is back. Checking the state file after shutdown (attached) I see that the entry for the printer is still in the file, so it seems that the state of the Printer Application did not get saved right after the deletion action nor in the beginning of the shutdown procedure. The log (in debug mode, attached) also does not show any saving of the state being happened after the deletion.

To Reproduce Start the PostScript Printer Application. If there is no printer listed in the web interface create one. Then click the "Delete" button and confirm the deletion. The deleted printer does not show on the main page any more. Now shut down the Printer Application (TERM signal or shutdown subcommand). In the state file or after starting the Printer Application again you see that the deleted printer is still there.

Expected behavior State file updated so that printer actually goes away.

System Information:

• As usual, Ubuntu 20.20 Groovy and the current GIT snapshots of PAPPL, cups-filters, and the PostScript Printer Application

Additional context

• State file after shutdown: ps_printer_app.state.txt
• Debug log, removal of "xxx" and shutdown in the end: log-delete-xxx.txt

[michaelrsweet]

Hmm, this should be working but I'll make sure.

[michaelrsweet]

[master a2116a6] Save state after deleting a printer - config change (Issue #75)