From c6c8f77bc03e48eae5b4c9b8bcbd9477d769a19a Mon Sep 17 00:00:00 2001
From: nicm <nicm>
Date: Wed, 10 Jun 2026 14:06:45 +0000
Subject: [PATCH] While grouped sessions are being killed, it can leave session
 which are not really useful as targets (no active pane or current window) in
 the tree. Make cmd_find_best_session skip these. GitHub issue 5167.

---
 cmd-find.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/cmd-find.c b/cmd-find.c
index 761f133f..88a276b3 100644
--- a/cmd-find.c
+++ b/cmd-find.c
@@ -148,6 +148,18 @@ cmd_find_session_better(struct session *s, struct session *than, int flags)
 	return (timercmp(&s->activity_time, &than->activity_time, >));
 }
 
+/* Can this session be usefully targeted? */
+static int
+cmd_find_session_valid(struct session *s)
+{
+	if (!session_alive(s) ||
+	    s->curw == NULL ||
+	    s->curw->window == NULL ||
+	    s->curw->window->active == NULL)
+		return (0);
+	return (1);
+}
+
 /* Find best session from a list, or all if list is NULL. */
 static struct session *
 cmd_find_best_session(struct session **slist, u_int ssize, int flags)
@@ -160,11 +172,15 @@ cmd_find_best_session(struct session **slist, u_int ssize, int flags)
 	s = NULL;
 	if (slist != NULL) {
 		for (i = 0; i < ssize; i++) {
+			if (!cmd_find_session_valid(slist[i]))
+				continue;
 			if (cmd_find_session_better(slist[i], s, flags))
 				s = slist[i];
 		}
 	} else {
 		RB_FOREACH(s_loop, sessions, &sessions) {
+			if (!cmd_find_session_valid(s_loop))
+				continue;
 			if (cmd_find_session_better(s_loop, s, flags))
 				s = s_loop;
 		}