re-place transient wl clients when parent is first sized

this should ensure more reliable centering using a nonzero geometry

src/bin/e_comp_wl.c

@@ -1431,6 +1431,17 @@ _e_comp_wl_surface_state_commit(E_Client *ec, E_Comp_Wl_Surface_State *state)
           }
         w = ec->client.w;
         h = ec->client.h;
+        if (ec->comp_data->need_center)
+          {
+             Eina_List *l;
+             E_Client *cec;
+             EINA_LIST_FOREACH(ec->transients, l, cec)
+               {
+                  cec->placed = 0;
+                  if (!cec->ignored) EC_CHANGED(cec);
+               }
+             ec->comp_data->need_center = 0;
+          }
      }
    else
      w = state->bw, h = state->bh;

src/bin/e_comp_wl.h

@@ -359,6 +359,7 @@ struct _E_Comp_Wl_Client_Data
    Eina_Bool need_xdg6_configure : 1;
    Eina_Bool maximize_anims_disabled : 1;
    Eina_Bool ssd_mouse_in : 1;
+   Eina_Bool need_center : 1;
 };
 
 struct _E_Comp_Wl_Output

src/bin/e_comp_wl_extensions.c

@@ -403,6 +403,7 @@ _e_comp_wl_zxdg_imported_v1_set_parent_of(struct wl_client *client EINA_UNUSED,
         evas_object_event_callback_add(ec->frame, EVAS_CALLBACK_DEL, _imported_del, im);
         e_client_parent_set(ec, im->ex->ec);
         ec->parent->lock_close = 1;
+        ec->parent->comp_data->need_center = 1;
      }
 }