Entering any character in the register when GTK_IM_MODULE=xim causes a segfault in Gnucash 3.0

1) Launch gnucash with GTK_IM_MODULE=xim and unset XMODIFIERS
2) Open the register and type any character

The following stack trace is obtained. The cause seems to be a NULL client_window in the GtkIMContextXIM instance.

Thread 1 "gnucash" received signal SIGSEGV, Segmentation fault.
0x00007ffff4315582 in gdk_window_has_impl (window=<optimized out>)
    at gdkwindow.c:677
677	gdkwindow.c: Aucun fichier ou dossier de ce type.
(gdb) bt

+ Trace 238538

$1 = {object = {parent_instance = {g_type_instance = {g_class = 0x555556bf3bd0}, ref_count = 1, qdata = 0x0}}, im_info = 0x0, 
  locale = 0x555555acbb00 "fr_FR.utf8", mb_charset = 0x555556b382d0 "UTF-8", client_window = 0x0, client_widget = 0x0, 
  status_window = 0x0, preedit_size = 0, preedit_length = 0, preedit_chars = 0x0, feedbacks = 0x0, preedit_cursor = 0, 
  preedit_start_callback = {client_data = 0x0, callback = 0x0}, preedit_done_callback = {client_data = 0x0, callback = 0x0}, 
  preedit_draw_callback = {client_data = 0x0, callback = 0x0}, preedit_caret_callback = {client_data = 0x0, callback = 0x0}, 
  status_start_callback = {client_data = 0x0, callback = 0x0}, status_done_callback = {client_data = 0x0, callback = 0x0}, 
  status_draw_callback = {client_data = 0x0, callback = 0x0}, string_conversion_callback = {client_data = 0x0, 
    callback = 0x0}, ic = 0x0, filter_key_release = 0, use_preedit = 1, finalizing = 0, in_toplevel = 0, has_focus = 1}