From 2cb758899c6fee8349cf14f21203a391f542b1ea Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Thu, 12 Mar 2026 12:43:25 -1000
Subject: [PATCH] Document str param as non-null in buf_append_str

---
 esphome/core/helpers.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/esphome/core/helpers.h b/esphome/core/helpers.h
index d28d53be023..b2517e2d7ac 100644
--- a/esphome/core/helpers.h
+++ b/esphome/core/helpers.h
@@ -947,7 +947,7 @@ __attribute__((format(printf, 4, 5))) inline size_t buf_append_printf(char *buf,
 /// @param buf Output buffer
 /// @param size Total buffer size
 /// @param pos Current position in buffer
-/// @param str String to append
+/// @param str String to append (must not be null)
 /// @return New position after appending (capped at size on overflow)
 inline size_t buf_append_str(char *buf, size_t size, size_t pos, const char *str) {
   if (pos >= size) {