[gtk/gtk-3-24: 1/5] wayland: Postpone window resize requests until configured

[Matthias Clasen <matthiasc src gnome org>]

commit 7f12dc2b66bba15b2e1c0ca077fa4ae58962ec0f
Author: Jonas Ådahl <jadahl gmail com>
Date:   Thu Apr 2 16:36:44 2020 +0200

    wayland: Postpone window resize requests until configured
    
    An application may want to set a fallback size of a window while still
    mapping maximized. This is done by calling gtk_window_resize() before
    gtk_window_maximize() and before gtk_window_show(). When the window is
    mapped, it should have a maximized size, and if it eventually is
    unmaximized, it should fall back to the size from the earlier
    gtk_window_resize() call.
    
    What happens before this commit is that the initial window size ends up
    respecting the first gtk_window_resize() dimensions, and not the window
    dimension configured by the Wayland display server (i.e. maximized
    dimensions).
    
    Fix this by postponing any configure events until we received our
    configuration from the display server. If we got one with a fixed size
    (e.g. we're maximized, tiled etc), we use that, otherwise we look at the
    one that was previously configured by gtk which corresponds to the
    "preferred" size when not being maximized.
    
    This fixes Firefox being started in a maximized state when using the
    Wayland backend.
    
    Closes: https://gitlab.gnome.org/GNOME/gtk/-/issues/2538

 gdk/wayland/gdkwindow-wayland.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
---
diff --git a/gdk/wayland/gdkwindow-wayland.c b/gdk/wayland/gdkwindow-wayland.c
index e863e568e8..ca91e78adc 100644
--- a/gdk/wayland/gdkwindow-wayland.c
+++ b/gdk/wayland/gdkwindow-wayland.c
@@ -203,6 +203,9 @@ struct _GdkWindowImplWayland
   int saved_width;
   int saved_height;
 
+  int unconfigured_width;
+  int unconfigured_height;
+
   gulong parent_surface_committed_handler;
 
   struct {
@@ -1083,6 +1086,13 @@ gdk_wayland_window_maybe_configure (GdkWindow *window,
       impl->scale == scale)
     return;
 
+  if (!impl->initial_configure_received)
+    {
+      impl->unconfigured_width = width;
+      impl->unconfigured_height = height;
+      return;
+    }
+
   /* For xdg_popup using an xdg_positioner, there is a race condition if
    * the application tries to change the size after it's mapped, but before
    * the initial configure is received, so hide and show the surface again
@@ -1578,6 +1588,14 @@ gdk_wayland_window_handle_configure (GdkWindow *window,
 
       gdk_wayland_window_configure (window, width, height, impl->scale);
     }
+  else
+    {
+      gdk_wayland_window_configure (window,
+                                    impl->unconfigured_width,
+                                    impl->unconfigured_height,
+                                    impl->scale);
+    }
+
 
   GDK_NOTE (EVENTS,
             g_message ("configure, window %p %dx%d,%s%s%s%s",