Fix crash when deleting last child in a tabbed or stacked container

There was no `current` child because the container was destroyed. This
makes it fall back to looking in the parent's current children list.

1 files changed, 16 insertions, 12 deletions

diff --git a/sway/desktop/output.c b/sway/desktop/output.c
index 9db95ef5..1ca48975 100644
--- a/sway/desktop/output.c
+++ b/sway/desktop/output.c
@@ -713,7 +713,7 @@ static void render_container_tabbed(struct sway_output *output,
         }
         struct sway_seat *seat = input_manager_current_seat(input_manager);
         struct sway_container *focus = seat_get_focus(seat);
-        struct sway_container *current = seat_get_active_child(seat, con);
+        struct sway_container *current = seat_get_active_current_child(seat, con);
         struct border_colors *current_colors = NULL;
         struct sway_container_state *pstate = &con->current;
 
@@ -756,11 +756,13 @@ static void render_container_tabbed(struct sway_output *output,
         }
 
         // Render surface and left/right/bottom borders
-        if (current->type == C_VIEW) {
-                render_view(output, damage, current, current_colors);
-        } else {
-                render_container(output, damage, current,
-                                parent_focused || current == focus);
+        if (current) {
+                if (current->type == C_VIEW) {
+                        render_view(output, damage, current, current_colors);
+                } else {
+                        render_container(output, damage, current,
+                                        parent_focused || current == focus);
+                }
         }
 }
 
@@ -775,7 +777,7 @@ static void render_container_stacked(struct sway_output *output,
         }
         struct sway_seat *seat = input_manager_current_seat(input_manager);
         struct sway_container *focus = seat_get_focus(seat);
-        struct sway_container *current = seat_get_active_child(seat, con);
+        struct sway_container *current = seat_get_active_current_child(seat, con);
         struct border_colors *current_colors = NULL;
         struct sway_container_state *pstate = &con->current;
 
@@ -812,11 +814,13 @@ static void render_container_stacked(struct sway_output *output,
         }
 
         // Render surface and left/right/bottom borders
-        if (current->type == C_VIEW) {
-                render_view(output, damage, current, current_colors);
-        } else {
-                render_container(output, damage, current,
-                                parent_focused || current == focus);
+        if (current) {
+                if (current->type == C_VIEW) {
+                        render_view(output, damage, current, current_colors);
+                } else {
+                        render_container(output, damage, current,
+                                        parent_focused || current == focus);
+                }
         }
 }