notify: separate active notifications from unfinished kitty notifications

This fixes an issue where it wasn't possible to trigger multiple
notifications with the same kitty notification ID. This is something
that works in kitty, and there's no reason why it shouldn't work.

The issue was that we track stdout, and the notification helper's PID
in the notification struct. Thus, when a notification is being
displayed, we can't re-use the same notification struct instance for
another notification.

This patch fixes this by adding a new notification list,
'active_notifications'. Whenever we detect that we need to track the
helper (notification want's to either focus the window on activation,
or send an event to the application), we add a copy of the
notification to the 'active' list.

The notification can then be removed from the 'kitty' list, allowing
kitty notifications to re-use the same ID over and over again, even if
old notifications are still being displayed.

notify.c

@@ -75,7 +75,7 @@ fdm_notify_stdout(struct fdm *fdm, int fd, int events, void *data)
 
 
     /* Find notification */
-    tll_foreach(term->notifications, it) {
+    tll_foreach(term->active_notifications, it) {
         if (it->item.stdout_fd == fd) {
             notif = &it->item;
             break;
@@ -124,7 +124,7 @@ notif_done(struct reaper *reaper, pid_t pid, int status, void *data)
 {
     struct terminal *term = data;
 
-    tll_foreach(term->notifications, it) {
+    tll_foreach(term->active_notifications, it) {
         struct notification *notif = &it->item;
         if (notif->pid != pid)
             continue;
@@ -148,17 +148,17 @@ notif_done(struct reaper *reaper, pid_t pid, int status, void *data)
         }
 
         notify_free(term, notif);
-        tll_remove(term->notifications, it);
+        tll_remove(term->active_notifications, it);
         return;
     }
 }
 
 bool
-notify_notify(const struct terminal *term, struct notification *notif)
+notify_notify(struct terminal *term, struct notification *notif)
 {
     xassert(notif->xdg_token == NULL);
     xassert(notif->pid == 0);
-    xassert(notif->stdout_fd == 0);
+    xassert(notif->stdout_fd <= 0);
     xassert(notif->stdout_data == NULL);
 
     notif->pid = -1;
@@ -187,6 +187,8 @@ notify_notify(const struct terminal *term, struct notification *notif)
         }
     }
 
+    bool track_notification = notif->focus || notif->report;
+
     LOG_DBG("notify: title=\"%s\", body=\"%s\"", title, body);
 
     xassert(title != NULL);
@@ -230,13 +232,25 @@ notify_notify(const struct terminal *term, struct notification *notif)
         LOG_DBG("  argv[%zu] = \"%s\"", i, argv[i]);
 
     int stdout_fds[2] = {-1, -1};
-    if ((notif->focus || notif->report) &&
-        pipe2(stdout_fds, O_CLOEXEC | O_NONBLOCK) < 0)
-    {
-        LOG_WARN("failed to create stdout pipe");
-        /* Non-fatal */
+    if (track_notification) {
+        if (pipe2(stdout_fds, O_CLOEXEC | O_NONBLOCK) < 0) {
+            LOG_WARN("failed to create stdout pipe");
+            track_notification = false;
+            /* Non-fatal */
+        } else {
+            tll_push_back(term->active_notifications, *notif);
+            notif->id = NULL;
+            notif->title = NULL;
+            notif->body = NULL;
+            notif->icon_id = NULL;
+            notif->icon_symbolic_name= NULL;
+            notif->icon_data = NULL;
+            notif->icon_data_sz = 0;
+            notif = &tll_back(term->active_notifications);
+        }
     }
 
+
     if (stdout_fds[0] >= 0) {
         xassert(notif->xdg_token == NULL);
         fdm_add(term->fdm, stdout_fds[0], EPOLLIN,
@@ -247,7 +261,7 @@ notify_notify(const struct terminal *term, struct notification *notif)
     int devnull = open("/dev/null", O_RDONLY);
     pid_t pid = spawn(
         term->reaper, NULL, argv, devnull, stdout_fds[1], -1,
-        &notif_done, (void *)term, NULL);
+        track_notification ? &notif_done : NULL, (void *)term, NULL);
 
     if (stdout_fds[1] >= 0) {
         /* Close write-end of stdout pipe */

notify.h

@@ -60,7 +60,7 @@ struct notification_icon {
     char *tmp_file_on_disk;
 };
 
-bool notify_notify(const struct terminal *term, struct notification *notif);
+bool notify_notify(struct terminal *term, struct notification *notif);
 void notify_free(struct terminal *term, struct notification *notif);
 
 void notify_icon_add(struct terminal *term, const char *id,

osc.c

@@ -727,7 +727,7 @@ kitty_notification(struct terminal *term, char *string)
 
     /* Search for an existing (d=0) notification to update */
     struct notification *notif = NULL;
-    tll_foreach(term->notifications, it) {
+    tll_foreach(term->kitty_notifications, it) {
         if (strcmp(it->item.id, id) == 0) {
             /* Found existing notification */
             notif = &it->item;
@@ -736,16 +736,17 @@ kitty_notification(struct terminal *term, char *string)
     }
 
     if (notif == NULL) {
-        tll_push_front(term->notifications, ((struct notification){
+        tll_push_front(term->kitty_notifications, ((struct notification){
             .id = id,
             .when = when,
             .urgency = urgency,
             .focus = focus,
             .report = report,
+            .stdout_fd = -1,
         }));
 
         id = NULL;   /* Prevent double free */
-        notif = &tll_front(term->notifications);
+        notif = &tll_front(term->kitty_notifications);
     }
 
     if (notif->pid > 0) {
@@ -833,15 +834,15 @@ kitty_notification(struct terminal *term, char *string)
          * The checks for title|body is to handle notifications that
          * only load icon data into the icon cache
          */
-        if ((notif->title != NULL || notif->body != NULL) &&
-            !notify_notify(term, notif))
-        {
-            tll_foreach(term->notifications, it) {
-                if (&it->item == notif) {
-                    notify_free(term, &it->item);
-                    tll_remove(term->notifications, it);
-                    break;
-                }
+        if (notif->title != NULL || notif->body != NULL) {
+            notify_notify(term, notif);
+        }
+
+        tll_foreach(term->kitty_notifications, it) {
+            if (&it->item == notif) {
+                notify_free(term, &it->item);
+                tll_remove(term->kitty_notifications, it);
+                break;
             }
         }
     }

terminal.c

@@ -1313,7 +1313,8 @@ term_init(const struct config *conf, struct fdm *fdm, struct reaper *reaper,
 #if defined(FOOT_IME_ENABLED) && FOOT_IME_ENABLED
         .ime_enabled = true,
 #endif
-        .notifications = tll_init(),
+        .kitty_notifications = tll_init(),
+        .active_notifications = tll_init(),
     };
 
     pixman_region32_init(&term->render.last_overlay_clip);
@@ -1818,9 +1819,14 @@ term_destroy(struct terminal *term)
         tll_remove(term->ptmx_paste_buffers, it);
     }
 
-    tll_foreach(term->notifications, it) {
+    tll_foreach(term->kitty_notifications, it) {
         notify_free(term, &it->item);
-        tll_remove(term->notifications, it);
+        tll_remove(term->kitty_notifications, it);
+    }
+
+    tll_foreach(term->active_notifications, it) {
+        notify_free(term, &it->item);
+        tll_remove(term->active_notifications, it);
     }
 
     for (size_t i = 0; i < ALEN(term->notification_icons); i++)
@@ -2031,9 +2037,14 @@ term_reset(struct terminal *term, bool hard)
         tll_remove(term->alt.sixel_images, it);
     }
 
-    tll_foreach(term->notifications, it) {
+    tll_foreach(term->kitty_notifications, it) {
         notify_free(term, &it->item);
-        tll_remove(term->notifications, it);
+        tll_remove(term->kitty_notifications, it);
+    }
+
+    tll_foreach(term->active_notifications, it) {
+        notify_free(term, &it->item);
+        tll_remove(term->active_notifications, it);
     }
 
     for (size_t i = 0; i < ALEN(term->notification_icons); i++)

terminal.h

@@ -801,7 +801,8 @@ struct terminal {
 
     /* Notifications that either haven't been sent yet, or have been
        sent but not yet dismissed */
-    tll(struct notification) notifications;
+    tll(struct notification) kitty_notifications;
+    tll(struct notification) active_notifications;
     struct notification_icon notification_icons[32];
 
     char *foot_exe;