From 00f3899aea035666fa9e7bd60bc7c2cf36c8e745 Mon Sep 17 00:00:00 2001
From: nicm <nicm@openbsd.org>
Date: Mon, 7 Sep 2026 12:05:12 +0000
Subject: [PATCH] Error on invalid relative targets, such as +foo or -0. GitHub
 issue 5576 from imcusg at gmail dot com.

---
 cmd-find.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/cmd-find.c b/cmd-find.c
index b872d9eff..461d44a2f 100644
--- a/cmd-find.c
+++ b/cmd-find.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-find.c,v 1.87 2026/07/17 12:42:51 nicm Exp $ */
+/* $OpenBSD: cmd-find.c,v 1.88 2026/09/07 12:05:12 nicm Exp $ */
 
 /*
  * Copyright (c) 2015 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -389,9 +389,11 @@ cmd_find_get_window_with_session(struct cmd_find_state *fs, const char *window)
 
 	/* Try as an offset. */
 	if (!exact && (window[0] == '+' || window[0] == '-')) {
-		if (window[1] != '\0')
-			n = strtonum(window + 1, 1, INT_MAX, NULL);
-		else
+		if (window[1] != '\0') {
+			n = strtonum(window + 1, 1, INT_MAX, &errstr);
+			if (errstr != NULL)
+				return (-1);
+		} else
 			n = 1;
 		s = fs->s;
 		if (fs->flags & CMD_FIND_WINDOW_INDEX) {
@@ -627,9 +629,11 @@ cmd_find_get_pane_with_window(struct cmd_find_state *fs, const char *pane)
 
 	/* Try as an offset. */
 	if (pane[0] == '+' || pane[0] == '-') {
-		if (pane[1] != '\0')
-			n = strtonum(pane + 1, 1, INT_MAX, NULL);
-		else
+		if (pane[1] != '\0') {
+			n = strtonum(pane + 1, 1, INT_MAX, &errstr);
+			if (errstr != NULL)
+				return (-1);
+		} else
 			n = 1;
 		wp = fs->w->active;
 		if (pane[0] == '+')