tests/stacking: Add test for checking restored positions

Going maximized -> unmaximized should restore the previous position. The
same for untiling, or going from tiled, to maximized, to floating.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1171

src/tests/meson.build

@@ -144,6 +144,7 @@ stacking_tests = [
   'restore-size',
   'unmaximize-new-size',
   'fullscreen-maximize',
+  'restore-position',
 ]
 
 foreach stacking_test: stacking_tests

src/tests/stacking/restore-position.metatest

@@ -0,0 +1,73 @@
+# X11
+
+new_client x x11
+create x/1 csd
+show x/1
+
+move x/1 100 100
+assert_position x/1 100 100
+
+maximize x/1
+wait_reconfigure
+assert_position x/1 0 0
+
+unmaximize x/1
+wait_reconfigure
+assert_position x/1 100 100
+
+tile x/1 left
+wait
+assert_position x/1 0 0
+
+untile x/1
+wait
+assert_position x/1 100 100
+
+tile x/1 left
+wait
+assert_position x/1 0 0
+
+maximize x/1
+wait_reconfigure
+assert_position x/1 0 0
+
+unmaximize x/1
+wait_reconfigure
+assert_position x/1 100 100
+
+# Wayland
+
+new_client w wayland
+create w/1 csd
+show w/1
+
+move w/1 100 100
+assert_position w/1 100 100
+
+maximize w/1
+wait_reconfigure
+assert_position w/1 0 0
+
+unmaximize w/1
+wait_reconfigure
+assert_position w/1 100 100
+
+tile w/1 left
+wait_reconfigure
+assert_position w/1 0 0
+
+untile w/1
+wait
+assert_position w/1 100 100
+
+tile w/1 left
+wait
+assert_position w/1 0 0
+
+maximize w/1
+wait_reconfigure
+assert_position w/1 0 0
+
+unmaximize w/1
+wait_reconfigure
+assert_position w/1 100 100