Description of problem: I have been opened "Flatpak Developer Demo" application and click "Print..." in menu of "Portals" button Version-Release number of selected component: xdg-desktop-portal-gtk-0.11-1.fc28 Additional info: reporter: libreport-2.9.5 backtrace_rating: 4 cmdline: /usr/libexec/xdg-desktop-portal-gtk crash_function: gtk_paper_size_free executable: /usr/libexec/xdg-desktop-portal-gtk journald_cursor: s=61f58f3f39f34be6881b38f5590feedf;i=13e83;b=dd65767559584d959bc9c754e6bd104e;m=610c4b6e5;t=56e3b779be5ae;x=d7777eda609a72a3 kernel: 4.16.13-300.fc28.x86_64 rootdir: / runlevel: N 5 type: CCpp uid: 1000 Truncated backtrace: Thread no. 1 (10 frames) #0 gtk_paper_size_free at gtkpapersize.c:554 #1 gtk_page_setup_new_from_gvariant at gtkpagesetup.c:906 #2 handle_prepare_print at src/print.c:627 #3 ffi_call_unix64 at ../src/x86/unix64.S:76 #4 ffi_call at ../src/x86/ffi64.c:525 #5 g_cclosure_marshal_generic at gclosure.c:1490 #8 g_signal_emitv at gsignal.c:3129 #9 _xdp_impl_print_skeleton_handle_method_call at src/xdg-desktop-portal-dbus.c:5877 #10 g_dbus_interface_method_dispatch_helper at gdbusinterfaceskeleton.c:609 #11 call_in_idle_cb at gdbusconnection.c:4851
Created attachment 1449467 [details] File: backtrace
Created attachment 1449468 [details] File: cgroup
Created attachment 1449469 [details] File: core_backtrace
Created attachment 1449470 [details] File: cpuinfo
Created attachment 1449471 [details] File: dso_list
Created attachment 1449472 [details] File: environ
Created attachment 1449473 [details] File: exploitable
Created attachment 1449474 [details] File: limits
Created attachment 1449475 [details] File: maps
Created attachment 1449476 [details] File: mountinfo
Created attachment 1449477 [details] File: open_fds
Created attachment 1449478 [details] File: proc_pid_status
Similar problem has been detected: Install flathub-demo (https://github.com/flatpak/qt-flatpak-demo) via flatpak and select print. reporter: libreport-2.9.5 backtrace_rating: 4 cmdline: /usr/libexec/xdg-desktop-portal-gtk crash_function: gtk_paper_size_free executable: /usr/libexec/xdg-desktop-portal-gtk journald_cursor: s=c86af0197c6e48e88ea1a8534f46c13d;i=277a86;b=f6109918440a43e286c48316c874eb35;m=d8e691d4;t=578a528e98caf;x=29a2b147982ca456 kernel: 4.18.13-200.fc28.x86_64 package: xdg-desktop-portal-gtk-1.0-1.fc28 reason: xdg-desktop-portal-gtk killed by SIGSEGV rootdir: / runlevel: N 5 type: CCpp uid: 1000
Also reported at https://github.com/flatpak/qt-flatpak-demo/issues/12 now.
I cannot reproduce this on Fedora 29, but I tried under Plasma running xdg-desktop-portal-gtk, which I think shouldn't make difference.
Can you maybe try it now with updated demo app. I found out that the pdf there was broken, it should be fixed now, but I'm not sure if this could cause this problem.
The latest version is v1.1.3 for me here.