Fix scratchpad fullscreen behavior and crash

When setting fullscreen on a hidden scratchpad container, there was a
check to see if there was an existing fullscreen container on the
workspace so it could be fullscreen disabled first. Since the workspace
is NULL, it would cause a SIGSEGV. This adds a NULL check to avoid the
crash.

This also changes the behavior of how fullscreen is handled when adding
a container to the scratchpad or changing visibility of a scratchpad
container to match i3's. The behavior is as follows:
- When adding a container to the scratchpad or hiding a container back
  into the scratchpad, there is an implicit fullscreen disable
- When setting fullscreen on a container that is hidden in the
  scratchpad, it will be fullscreen when shown (and fullscreen disabled
  when hidden as stated above)
- When setting fullscreen global on a container that is hidden in the
  scratchpad, it will be shown immediately as fullscreen global. The
  container is not moved to a workspace and remains in the
  scratchpad. The container will be visible until fullscreen disabled
  or killed. Since the container is in the scratchpad, running
  `scratchpad show` or `move container to scratchpad` will have no
  effect

This also changes `container_replace` to transfer fullscreen and
scratchpad status.

1 files changed, 41 insertions, 21 deletions

diff --git a/sway/tree/view.c b/sway/tree/view.c
index 2c8839f5..c241b2b3 100644
--- a/sway/tree/view.c
+++ b/sway/tree/view.c
@@ -197,10 +197,11 @@ static bool gaps_to_edge(struct sway_view *view) {
 
 void view_autoconfigure(struct sway_view *view) {
         struct sway_container *con = view->container;
-        if (container_is_scratchpad_hidden(con)) {
+        if (container_is_scratchpad_hidden(con) &&
+                        con->fullscreen_mode != FULLSCREEN_GLOBAL) {
                 return;
         }
-        struct sway_output *output = con->workspace->output;
+        struct sway_output *output = con->workspace ? con->workspace->output : NULL;
 
         if (con->fullscreen_mode == FULLSCREEN_WORKSPACE) {
                 con->content_x = output->lx;
@@ -226,19 +227,21 @@ void view_autoconfigure(struct sway_view *view) {
 
         con->border_top = con->border_bottom = true;
         con->border_left = con->border_right = true;
-        if (config->hide_edge_borders == E_BOTH
-                        || config->hide_edge_borders == E_VERTICAL
-                        || (smart && !other_views && no_gaps)) {
-                con->border_left = con->x - con->current_gaps.left != ws->x;
-                int right_x = con->x + con->width + con->current_gaps.right;
-                con->border_right = right_x != ws->x + ws->width;
-        }
-        if (config->hide_edge_borders == E_BOTH
-                        || config->hide_edge_borders == E_HORIZONTAL
-                        || (smart && !other_views && no_gaps)) {
-                con->border_top = con->y - con->current_gaps.top != ws->y;
-                int bottom_y = con->y + con->height + con->current_gaps.bottom;
-                con->border_bottom = bottom_y != ws->y + ws->height;
+        if (ws) {
+                if (config->hide_edge_borders == E_BOTH
+                                || config->hide_edge_borders == E_VERTICAL
+                                || (smart && !other_views && no_gaps)) {
+                        con->border_left = con->x - con->current_gaps.left != ws->x;
+                        int right_x = con->x + con->width + con->current_gaps.right;
+                        con->border_right = right_x != ws->x + ws->width;
+                }
+                if (config->hide_edge_borders == E_BOTH
+                                || config->hide_edge_borders == E_HORIZONTAL
+                                || (smart && !other_views && no_gaps)) {
+                        con->border_top = con->y - con->current_gaps.top != ws->y;
+                        int bottom_y = con->y + con->height + con->current_gaps.bottom;
+                        con->border_bottom = bottom_y != ws->y + ws->height;
+                }
         }
 
         double y_offset = 0;
@@ -247,7 +250,8 @@ void view_autoconfigure(struct sway_view *view) {
         // title area. We have to offset the surface y by the height of the title,
         // bar, and disable any top border because we'll always have the title bar.
         list_t *siblings = container_get_siblings(con);
-        bool show_titlebar = siblings->length > 1 || !config->hide_lone_tab;
+        bool show_titlebar = (siblings && siblings->length > 1)
+                || !config->hide_lone_tab;
         if (show_titlebar && !container_is_floating(con)) {
                 enum sway_container_layout layout = container_parent_layout(con);
                 if (layout == L_TABBED) {
@@ -538,6 +542,10 @@ static bool should_focus(struct sway_view *view) {
         struct sway_workspace *prev_ws = seat_get_focused_workspace(seat);
         struct sway_workspace *map_ws = view->container->workspace;
 
+        if (view->container->fullscreen_mode == FULLSCREEN_GLOBAL) {
+                return true;
+        }
+
         // Views can only take focus if they are mapped into the active workspace
         if (prev_ws != map_ws) {
                 return false;
@@ -581,7 +589,8 @@ void view_map(struct sway_view *view, struct wlr_surface *wlr_surface,
         }
 
         struct sway_seat *seat = input_manager_current_seat();
-        struct sway_node *node = seat_get_focus_inactive(seat, &ws->node);
+        struct sway_node *node = ws ? seat_get_focus_inactive(seat, &ws->node)
+                : seat_get_focus_inactive(seat, &root->node);
         struct sway_container *target_sibling = node->type == N_CONTAINER ?
                 node->sway_container : NULL;
 
@@ -589,12 +598,13 @@ void view_map(struct sway_view *view, struct wlr_surface *wlr_surface,
         // launch it as a tiled view in the root of the workspace instead.
         if (target_sibling && container_is_floating(target_sibling)) {
                 target_sibling = NULL;
+                ws = seat_get_last_known_workspace(seat);
         }
 
         view->container = container_create(view);
         if (target_sibling) {
                 container_add_sibling(target_sibling, view->container, 1);
-        } else {
+        } else if (ws) {
                 workspace_add_tiling(ws, view->container);
         }
         ipc_event_window(view->container, "new");
@@ -1032,8 +1042,18 @@ bool view_is_visible(struct sway_view *view) {
                 return false;
         }
         struct sway_workspace *workspace = view->container->workspace;
-        if (!workspace) {
-                return false;
+        if (!workspace && view->container->fullscreen_mode != FULLSCREEN_GLOBAL) {
+                bool fs_global_descendant = false;
+                struct sway_container *parent = view->container->parent;
+                while (parent) {
+                        if (parent->fullscreen_mode == FULLSCREEN_GLOBAL) {
+                                fs_global_descendant = true;
+                        }
+                        parent = parent->parent;
+                }
+                if (!fs_global_descendant) {
+                        return false;
+                }
         }
         // Determine if view is nested inside a floating container which is sticky
         struct sway_container *floater = view->container;
@@ -1041,7 +1061,7 @@ bool view_is_visible(struct sway_view *view) {
                 floater = floater->parent;
         }
         bool is_sticky = container_is_floating(floater) && floater->is_sticky;
-        if (!is_sticky && !workspace_is_visible(workspace)) {
+        if (!is_sticky && workspace && !workspace_is_visible(workspace)) {
                 return false;
         }
         // Check view isn't in a tabbed or stacked container on an inactive tab