I changed the import assistant window to a modal window such that
the other windows cannot be changed while the import is ongoing.
There are problems when the main window is closed during the import.
Closing: https://savannah.gnu.org/bugs/?62448
_("Importing Delimited Text Data"));
gtk_window_set_icon_name (GTK_WINDOW (ia), "pspp");
_("Importing Delimited Text Data"));
gtk_window_set_icon_name (GTK_WINDOW (ia), "pspp");
+ gtk_window_set_modal (GTK_WINDOW(ia), TRUE);
chooser_page_create (ia);
chooser_page_create (ia);