window: Fix window size snapping back

We were not updating the remembered size at all when
the window is interactively resized, causing it to
snap back to its default size the next time we call
gdk_toplevel_present().

This is a bandaid fix to prevent very broken resizing
behavior, until we have properly redone toplevel sizing.

Fixes: #3076

gtk/gtkwindow.c

@@ -4729,6 +4729,22 @@ surface_size_changed (GtkWidget *widget,
 
   check_scale_changed (GTK_WINDOW (widget));
 
+  if (!(priv->state & (GDK_TOPLEVEL_STATE_FULLSCREEN |
+                       GDK_TOPLEVEL_STATE_MAXIMIZED |
+                       GDK_TOPLEVEL_STATE_TILED |
+                       GDK_TOPLEVEL_STATE_TOP_TILED |
+                       GDK_TOPLEVEL_STATE_RIGHT_TILED |
+                       GDK_TOPLEVEL_STATE_BOTTOM_TILED |
+                       GDK_TOPLEVEL_STATE_LEFT_TILED |
+                       GDK_TOPLEVEL_STATE_MINIMIZED)))
+    {
+      GtkWindowGeometryInfo *info;
+
+      info = gtk_window_get_geometry_info (GTK_WINDOW (widget), TRUE);
+      info->last.configure_request.width = width;
+      info->last.configure_request.height = height;
+    }
+
   /* priv->configure_request_count incremented for each
    * configure request, and decremented to a min of 0 for
    * each configure notify.
@@ -5490,7 +5506,6 @@ gtk_window_move_resize (GtkWindow *window)
   info->last.geometry = new_geometry;
   info->last.flags = new_flags;
   info->last.configure_request = new_request;
-
   /* need to set PPosition so the WM will look at our position,
    * but we don't want to count PPosition coming and going as a hints
    * change for future iterations. So we saved info->last prior to