criteria: fix __focused__ when no focus or unset

This fixes the behavior of `__focused__` when there is no focused view
to match i3's behavior of successfully matching no views instead of
returning an error of a missing value. It also applies the same logic
when a token is not applicable (or unset) for a view such as `app_id`
for a focused xwayland view or `class` for a focused xdg-shell view.

This adds an `autofail` boolean to `struct criteria`. If it is set to
`true`, then `criteria_matches_view` will immediately bail out as a
no match. If `autofail` is set, the criteria will also not be
considered empty by `criteria_is_empty`.

To set this new `autofail` property, `get_focused_prop` will now take
in a boolean pointer of the same name. If `__focused__` is supported
for the token and there is no focused view or the focused view does not
have a value for the token, then the boolean will be set to true. In
`parse_token`, the boolean value will be checked and if set to true,
then `criteria->autofail` will be set to true and `parse_token` will
bail successfully. Tokens will still be parsed to make sure the whole
criteria is syntactically valid, which is also why
`&criteria->autofail` is not passed to `get_focused_prop` and a local
boolean is declared in `parse_token`.

1 files changed, 49 insertions, 22 deletions

diff --git a/sway/criteria.c b/sway/criteria.c
index f2db6c18..11b41f35 100644
--- a/sway/criteria.c
+++ b/sway/criteria.c
@@ -16,7 +16,8 @@
 #include "config.h"
 
 bool criteria_is_empty(struct criteria *criteria) {
-        return !criteria->title
+        return !criteria->autofail
+                && !criteria->title
                 && !criteria->shell
                 && !criteria->app_id
                 && !criteria->con_mark
@@ -98,6 +99,10 @@ static void find_urgent_iterator(struct sway_container *con, void *data) {
 
 static bool criteria_matches_view(struct criteria *criteria,
                 struct sway_view *view) {
+        if (criteria->autofail) {
+                return false;
+        }
+
         if (criteria->title) {
                 const char *title = view_get_title(view);
                 if (!title || regex_cmp(title, criteria->title) != 0) {
@@ -366,50 +371,66 @@ static enum criteria_token token_from_name(char *name) {
  * using criteria via IPC. Using __focused__ in config is not useful because
  * criteria is only executed once per view.
  */
-static char *get_focused_prop(enum criteria_token token) {
+static char *get_focused_prop(enum criteria_token token, bool *autofail) {
         struct sway_seat *seat = input_manager_current_seat();
         struct sway_container *focus = seat_get_focused_container(seat);
 
-        if (!focus || !focus->view) {
-                return NULL;
-        }
-        struct sway_view *view = focus->view;
+        struct sway_view *view = focus ? focus->view : NULL;
         const char *value = NULL;
 
         switch (token) {
         case T_APP_ID:
-                value = view_get_app_id(view);
+                *autofail = true;
+                if (view) {
+                        value = view_get_app_id(view);
+                }
                 break;
         case T_SHELL:
-                value = view_get_shell(view);
+                *autofail = true;
+                if (view) {
+                        value = view_get_shell(view);
+                }
                 break;
         case T_TITLE:
-                value = view_get_title(view);
+                *autofail = true;
+                if (view) {
+                        value = view_get_title(view);
+                }
                 break;
         case T_WORKSPACE:
-                if (focus->workspace) {
+                *autofail = true;
+                if (focus && focus->workspace) {
                         value = focus->workspace->name;
                 }
                 break;
         case T_CON_ID:
-                if (view->container == NULL) {
-                        return NULL;
-                }
-                size_t id = view->container->node.id;
-                size_t id_size = snprintf(NULL, 0, "%zu", id) + 1;
-                char *id_str = malloc(id_size);
-                snprintf(id_str, id_size, "%zu", id);
-                value = id_str;
+                *autofail = true;
+                if (view && view->container) {
+                        size_t id = view->container->node.id;
+                        size_t id_size = snprintf(NULL, 0, "%zu", id) + 1;
+                        char *id_str = malloc(id_size);
+                        snprintf(id_str, id_size, "%zu", id);
+                        value = id_str;
+                }
                 break;
 #if HAVE_XWAYLAND
         case T_CLASS:
-                value = view_get_class(view);
+                *autofail = true;
+                if (view) {
+                        value = view_get_class(view);
+                }
                 break;
         case T_INSTANCE:
-                value = view_get_instance(view);
+                *autofail = true;
+                if (view) {
+                        value = view_get_instance(view);
+                }
                 break;
         case T_WINDOW_ROLE:
-                value = view_get_window_role(view);
+                *autofail = true;
+                if (view) {
+                        value = view_get_window_role(view);
+                }
                 break;
         case T_WINDOW_TYPE: // These do not support __focused__
         case T_ID:
@@ -419,6 +440,7 @@ static char *get_focused_prop(enum criteria_token token) {
         case T_TILING:
         case T_URGENT:
         case T_INVALID:
+                *autofail = false;
                 break;
         }
         if (value) {
@@ -439,7 +461,12 @@ static bool parse_token(struct criteria *criteria, char *name, char *value) {
 
         char *effective_value = NULL;
         if (value && strcmp(value, "__focused__") == 0) {
-                effective_value = get_focused_prop(token);
+                bool autofail = false;
+                effective_value = get_focused_prop(token, &autofail);
+                if (!effective_value && autofail) {
+                        criteria->autofail = true;
+                        return true;
+                }
         } else if (value) {
                 effective_value = strdup(value);
         }