files saved from within firefox get lost

[myrdd]

I did not investigate this issue, but here's how to reproduce it:

• LD_PRELOAD=/usr/local/lib/kgtk/libkgtk3.so.5:$LD_PRELOAD firefox-esr
• either download a file to the local hard disk, or save a web page (ctrl+s)
• open the destination directory. the file is not there.

[myrdd]

@sr-tream are you able to reproduce this problem?

(BTW, in the gtk-wrapper script, firefox is not configured, yet.)

[sr-tream]

I'm use firefox with KDE patches by OpenSUSE. But palemoon was crashed after closing save dialog. And file isn't saving.
env LD_PRELOAD="/usr/local/lib64/kgtk/libkgtk2.so.5" palemoon

UPD: Installed firefox without KDE patches, it also crashes after closing the dialog. File isn't saving.

[myrdd]

I get the following messages/errors:

When the save dialog is opened:

(firefox-esr:2899): GLib-GObject-CRITICAL **: g_object_new_valist: object class 'GtkFileChooserDialog' has no property named 'file-system-backend'
Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged.

When the save dialog is closed (click ”save“):

(firefox-esr:2899): Gdk-CRITICAL **: gdk_window_set_cursor: assertion 'GDK_IS_WINDOW (window)' failed
(firefox-esr:2899): Gdk-CRITICAL **: gdk_window_set_cursor: assertion 'GDK_IS_WINDOW (window)' failed
(firefox-esr:2899): Gdk-CRITICAL **: gdk_window_get_scale_factor: assertion 'GDK_IS_WINDOW (window)' failed
(firefox-esr:2899): Gdk-CRITICAL **: gdk_window_get_scale_factor: assertion 'GDK_IS_WINDOW (window)' failed
(firefox-esr:2899): Gdk-CRITICAL **: gdk_window_get_scale_factor: assertion 'GDK_IS_WINDOW (window)' failed
(firefox-esr:2899): Gdk-CRITICAL **: gdk_window_set_cursor: assertion 'GDK_IS_WINDOW (window)' failed
(firefox-esr:2899): Gdk-CRITICAL **: gdk_window_set_cursor: assertion 'GDK_IS_WINDOW (window)' failed
(firefox-esr:2899): Gdk-CRITICAL **: gdk_window_set_cursor: assertion 'GDK_IS_WINDOW (window)' failed
(firefox-esr:2899): Gdk-CRITICAL **: gdk_window_get_scale_factor: assertion 'GDK_IS_WINDOW (window)' failed
(firefox-esr:2899): Gdk-CRITICAL **: gdk_window_get_scale_factor: assertion 'GDK_IS_WINDOW (window)' failed
(firefox-esr:2899): Gdk-CRITICAL **: gdk_window_get_scale_factor: assertion 'GDK_IS_WINDOW (window)' failed
(firefox-esr:2899): Gdk-CRITICAL **: gdk_window_set_cursor: assertion 'GDK_IS_WINDOW (window)' failed

I guess the file-system-backend needs to be implemented. See https://developer.gnome.org/pygtk/stable/class-gtkfilechooser.html#properties-gtkfilechooser