[gnome-2048] Do not save tiled window size.

[Arnaud B. <arnaudb src gnome org>]

commit c0bdebaee52a39f1f252aa0d0873b8a194d82f5f
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Sun Feb 3 17:19:56 2019 +0100

    Do not save tiled window size.
    
    It is hard to restore window in
    tiled state so do not try that.
    But, we can at least make that,
    if the window is half-maximized
    or tiled, we only keep the size
    in use for non-maximized state.

 src/application.vala | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)
---
diff --git a/src/application.vala b/src/application.vala
index e61fa53..f1e8b3e 100644
--- a/src/application.vala
+++ b/src/application.vala
@@ -28,6 +28,7 @@ private class Application : Gtk.Application
     private int _window_width;
     private int _window_height;
     private bool _window_maximized;
+    private bool _window_is_tiled;
 
     private int WINDOW_MINIMUM_SIZE_HEIGHT = 600;
     private int WINDOW_MINIMUM_SIZE_WIDTH = 600;
@@ -490,15 +491,24 @@ private class Application : Gtk.Application
 
     private void window_size_allocate_cb ()
     {
-        if (_window_maximized)
+        if (_window_maximized || _window_is_tiled)
             return;
-        _window.get_size (out _window_width, out _window_height);
+        int? window_width = null;
+        int? window_height = null;
+        _window.get_size (out window_width, out window_height);
+        if (window_width == null || window_height == null)
+            return;
+        _window_width = (!) window_width;
+        _window_height = (!) window_height;
     }
 
     private bool window_state_event_cb (Gdk.EventWindowState event)
     {
         if ((event.changed_mask & Gdk.WindowState.MAXIMIZED) != 0)
             _window_maximized = (event.new_window_state & Gdk.WindowState.MAXIMIZED) != 0;
+        /* We don’t save this state, but track it for saving size allocation */
+        if ((event.changed_mask & Gdk.WindowState.TILED) != 0)
+            _window_is_tiled = (event.new_window_state & Gdk.WindowState.TILED) != 0;
 
         return false;
     }