bug#32207: 26.1; can't set window position with emacs 26.3

[emacs]

> I couldn't tell.  If you run Emacs 25 and 26 in parallel...

Compiled 25 and ran "emacs -Q -g ...'.  It places the window
fine, but ...

Shell warnings:
---------------
(emacs:23708): Gtk-WARNING **: 10:59:27.659:
  gtk_window_parse_geometry() called on a window with no
  visible children; the window should be set up before
  gtk_window_parse_geometry() is called.

Fvwm warnings (some duplicated for some reason):
------------------------------------------------
[fvwm.0][__explain_placement]: placed new window 0x600122 'emacs@...':
  initial size 404x420
  desk 0 (current desk)
  current page
  position 400 400  (used user specified position)

[fvwm.0][GetWindowSizeHints]: <<WARNING>> reason: 6: The hints have been 
ignored because the window's current size would have become invalid.  The new 
hints will become active when the window generates the next ConfigureRequest.

[fvwm.0][GetWindowSizeHints]: <<WARNING>> The application window (id 0x600122)
  "emacs@..." has broken size hints (inconsistent with current size).
    fvwm is ignoring those hints.    hint override = 0, flags = 350
  min_width = 41, min_height = 84, max_width = 41, max_height = 84
  width_inc = 9, height_inc = 18
  min_aspect = 0/0, max_aspect = 0/0
  base_width = 41, base_height = 84
  win_gravity = 1

    If you are having a problem with the application, send a bug report
    with this message included to the application owner.
    There is no need to notify fvwm-workers@fvwm.org.

[fvwm.0][GetWindowSizeHints]: <<WARNING>> reason: 6: The hints have been 
ignored because the window's current size would have become invalid.  The new 
hints will become active when the window generates the next ConfigureRequest.

[fvwm.0][GetWindowSizeHints]: <<WARNING>> The application window (id 0x600122)
  "emacs@..." has broken size hints (inconsistent with current size).
    fvwm is ignoring those hints.    hint override = 0, flags = 350
  min_width = 41, min_height = 84, max_width = 41, max_height = 84
  width_inc = 9, height_inc = 18
  min_aspect = 0/0, max_aspect = 0/0
  base_width = 41, base_height = 84
  win_gravity = 1

    If you are having a problem with the application, send a bug report
    with this message included to the application owner.
    There is no need to notify fvwm-workers@fvwm.org.


Thus the position and size are fine, but it does generate a
lot of warnings!

-- Henrique