Add infrastructure to work out the best target given a pane or window

alone and use it to add pane_died and pane_exited hooks.

cmd-attach-session.c

@@ -144,7 +144,7 @@ cmd_attach_session(struct cmd_q *cmdq, int dflag, int rflag, const char *cflag,
 
 		if (~c->flags & CLIENT_CONTROL)
 			proc_send(c->peer, MSG_READY, -1, NULL, 0);
-		hooks_run(c->session->hooks, c, "client-attached");
+		hooks_run(c->session->hooks, c, NULL, "client-attached");
 		cmdq->client_exit = 0;
 	}
 	recalculate_sizes();

cmd-find.c

@@ -190,7 +190,7 @@ cmd_find_best_session_with_window(struct cmd_find_state *fs)
 	u_int		  ssize;
 	struct session	 *s;
 
-	if (fs->cmdq->client != NULL) {
+	if (fs->cmdq != NULL && fs->cmdq->client != NULL) {
 		fs->s = cmd_find_try_TMUX(fs->cmdq->client, fs->w);
 		if (fs->s != NULL)
 			return (cmd_find_best_winlink_with_window(fs));
@@ -254,7 +254,7 @@ cmd_find_current_session_with_client(struct cmd_find_state *fs)
 	 * sessions to those containing that pane (we still use the current
 	 * window in the best session).
 	 */
-	if (fs->cmdq->client->tty.path != NULL) {
+	if (fs->cmdq != NULL && fs->cmdq->client->tty.path != NULL) {
 		RB_FOREACH(wp, window_pane_tree, &all_window_panes) {
 			if (strcmp(wp->tty, fs->cmdq->client->tty.path) == 0)
 				break;
@@ -289,7 +289,9 @@ cmd_find_current_session_with_client(struct cmd_find_state *fs)
 	return (0);
 
 unknown_pane:
-	fs->s = cmd_find_try_TMUX(fs->cmdq->client, NULL);
+	fs->s = NULL;
+	if (fs->cmdq != NULL)
+		fs->s = cmd_find_try_TMUX(fs->cmdq->client, NULL);
 	if (fs->s == NULL)
 		fs->s = cmd_find_best_session(NULL, 0, fs->flags);
 	if (fs->s == NULL)
@@ -310,7 +312,7 @@ int
 cmd_find_current_session(struct cmd_find_state *fs)
 {
 	/* If we know the current client, use it. */
-	if (fs->cmdq->client != NULL) {
+	if (fs->cmdq != NULL && fs->cmdq->client != NULL) {
 		log_debug("%s: have client %p%s", __func__, fs->cmdq->client,
 		    fs->cmdq->client->session == NULL ? "" : " (with session)");
 		if (fs->cmdq->client->session == NULL)
@@ -862,6 +864,49 @@ cmd_find_log_state(const char *prefix, struct cmd_find_state *fs)
 		log_debug("%s: idx=none", prefix);
 }
 
+/* Find state from a session. */
+int
+cmd_find_from_session(struct cmd_find_state *fs, struct session *s)
+{
+	cmd_find_clear_state(fs, NULL, 0);
+
+	fs->s = s;
+	fs->wl = fs->s->curw;
+	fs->w = fs->wl->window;
+	fs->wp = fs->w->active;
+
+	cmd_find_log_state(__func__, fs);
+	return (0);
+}
+
+/* Find state from a window. */
+int
+cmd_find_from_window(struct cmd_find_state *fs, struct window *w)
+{
+	cmd_find_clear_state(fs, NULL, 0);
+
+	fs->w = w;
+	if (cmd_find_best_session_with_window(fs) != 0)
+		return (-1);
+	if (cmd_find_best_winlink_with_window(fs) != 0)
+		return (-1);
+
+	cmd_find_log_state(__func__, fs);
+	return (0);
+}
+
+/* Find state from a pane. */
+int
+cmd_find_from_pane(struct cmd_find_state *fs, struct window_pane *wp)
+{
+	if (cmd_find_from_window(fs, wp->window) != 0)
+		return (-1);
+	fs->wp = wp;
+
+	cmd_find_log_state(__func__, fs);
+	return (0);
+}
+
 /*
  * Split target into pieces and resolve for the given type. Fills in the given
  * state. Returns 0 on success or -1 on error.

cmd-queue.c

@@ -44,6 +44,9 @@ cmdq_new(struct client *c)
 	cmdq->item = NULL;
 	cmdq->cmd = NULL;
 
+	cmd_find_clear_state(&cmdq->current, NULL, 0);
+	cmdq->parent = NULL;
+
 	return (cmdq);
 }
 
@@ -286,3 +289,4 @@ cmdq_flush(struct cmd_q *cmdq)
 	}
 	cmdq->item = NULL;
 }
+

cmd-respawn-window.c

@@ -90,7 +90,7 @@ cmd_respawn_window_exec(struct cmd *self, struct cmd_q *cmdq)
 		cmdq_error(cmdq, "respawn window failed: %s", cause);
 		free(cause);
 		environ_free(env);
-		server_destroy_pane(wp);
+		server_destroy_pane(wp, 0);
 		return (CMD_RETURN_ERROR);
 	}
 	layout_init(w, wp);

hooks.c

@@ -42,6 +42,14 @@ hooks_cmp(struct hook *hook1, struct hook *hook2)
 	return (strcmp(hook1->name, hook2->name));
 }
 
+struct hooks *
+hooks_get(struct session *s)
+{
+	if (s != NULL)
+		return (s->hooks);
+	return (global_hooks);
+}
+
 struct hooks *
 hooks_create(struct hooks *parent)
 {
@@ -148,7 +156,8 @@ hooks_emptyfn(struct cmd_q *hooks_cmdq)
 }
 
 int
-hooks_run(struct hooks *hooks, struct client *c, const char *fmt, ...)
+hooks_run(struct hooks *hooks, struct client *c, struct cmd_find_state *fs,
+    const char *fmt, ...)
 {
 	struct hook	*hook;
 	struct cmd_q	*hooks_cmdq;
@@ -169,6 +178,9 @@ hooks_run(struct hooks *hooks, struct client *c, const char *fmt, ...)
 
 	hooks_cmdq = cmdq_new(c);
 	hooks_cmdq->flags |= CMD_Q_NOHOOKS;
+
+	if (fs != NULL)
+		cmd_find_copy_state(&hooks_cmdq->current, fs);
 	hooks_cmdq->parent = NULL;
 
 	cmdq_run(hooks_cmdq, hook->cmdlist, NULL);
@@ -177,7 +189,8 @@ hooks_run(struct hooks *hooks, struct client *c, const char *fmt, ...)
 }
 
 int
-hooks_wait(struct hooks *hooks, struct cmd_q *cmdq, const char *fmt, ...)
+hooks_wait(struct hooks *hooks, struct cmd_q *cmdq, struct cmd_find_state *fs,
+    const char *fmt, ...)
 {
 	struct hook	*hook;
 	struct cmd_q	*hooks_cmdq;
@@ -198,6 +211,9 @@ hooks_wait(struct hooks *hooks, struct cmd_q *cmdq, const char *fmt, ...)
 
 	hooks_cmdq = cmdq_new(cmdq->client);
 	hooks_cmdq->flags |= CMD_Q_NOHOOKS;
+
+	if (fs != NULL)
+		cmd_find_copy_state(&hooks_cmdq->current, fs);
 	hooks_cmdq->parent = cmdq;
 
 	hooks_cmdq->emptyfn = hooks_emptyfn;

server-client.c

@@ -283,7 +283,7 @@ server_client_detach(struct client *c, enum msgtype msgtype)
 	if (s == NULL)
 		return;
 
-	hooks_run(c->session->hooks, c, "client-detached");
+	hooks_run(c->session->hooks, c, NULL, "client-detached");
 	proc_send_s(c->peer, msgtype, s->name);
 }
 
@@ -1027,7 +1027,7 @@ server_client_dispatch(struct imsg *imsg, void *arg)
 			server_redraw_client(c);
 		}
 		if (c->session != NULL)
-			hooks_run(c->session->hooks, c, "client-resized");
+			hooks_run(c->session->hooks, c, NULL, "client-resized");
 		break;
 	case MSG_EXITING:
 		if (datalen != 0)

server-fn.c

@@ -293,12 +293,13 @@ server_unlink_window(struct session *s, struct winlink *wl)
 }
 
 void
-server_destroy_pane(struct window_pane *wp)
+server_destroy_pane(struct window_pane *wp, int hooks)
 {
 	struct window		*w = wp->window;
 	int			 old_fd;
 	struct screen_write_ctx	 ctx;
 	struct grid_cell	 gc;
+	struct cmd_find_state	 fs;
 
 	old_fd = wp->fd;
 	if (wp->fd != -1) {
@@ -319,13 +320,19 @@ server_destroy_pane(struct window_pane *wp)
 		screen_write_puts(&ctx, &gc, "Pane is dead");
 		screen_write_stop(&ctx);
 		wp->flags |= PANE_REDRAW;
+
+		if (hooks && cmd_find_from_pane(&fs, wp) == 0)
+			hooks_run(hooks_get(fs.s), NULL, &fs, "pane-died");
 		return;
 	}
 
 	server_unzoom_window(w);
 	layout_close_pane(wp);
 	window_remove_pane(w, wp);
 
+	if (hooks && cmd_find_from_window(&fs, w) == 0)
+		hooks_run(hooks_get(fs.s), NULL, &fs, "pane-exited");
+
 	if (TAILQ_EMPTY(&w->panes))
 		server_kill_window(w);
 	else

server.c

@@ -387,7 +387,7 @@ server_child_exited(pid_t pid, int status)
 		TAILQ_FOREACH(wp, &w->panes, entry) {
 			if (wp->pid == pid) {
 				wp->status = status;
-				server_destroy_pane(wp);
+				server_destroy_pane(wp, 1);
 				break;
 			}
 		}

tmux.1

@@ -3230,6 +3230,12 @@ Run when a client is attached.
 Run when a client is detached
 .It client-resized
 Run when a client is resized.
+.It pane-died
+Run when the program running in a pane exits, but
+.Ic remain-on-exit
+is on so the pane has not closed.
+.It pane-exited
+Run when the program running in a pane exits.
 .El
 .Pp
 Hooks are managed with these commands:

window.c

@@ -974,7 +974,7 @@ window_pane_error_callback(__unused struct bufferevent *bufev,
 {
 	struct window_pane *wp = data;
 
-	server_destroy_pane(wp);
+	server_destroy_pane(wp, 1);
 }
 
 void