From b83f7b8e16e3e88bb182e39579272d094f7be67b Mon Sep 17 00:00:00 2001
From: Jonas Rabenstein <jonas.rabenstein@emlix.com>
Date: Sat, 27 Dec 2025 20:52:21 +0100
Subject: [PATCH] fixup! use esphome::crc16

---
 components/brmesh/network.cpp | 17 +++++------------
 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/components/brmesh/network.cpp b/components/brmesh/network.cpp
index b0e68f1..9f39e33 100644
--- a/components/brmesh/network.cpp
+++ b/components/brmesh/network.cpp
@@ -65,17 +65,6 @@ uint8_t crc(const std::span<uint8_t, size> &bytes, uint8_t init = 0x00) {
     return init;
 }
 
-uint16_t crc16(const std::span<const uint8_t> &data, const uint16_t seed = 0xFFFF) {
-  return ~esphome::crc16(
-      data.data(),
-      data.size(),
-      seed,
-      0x1021,
-      true,   // refin
-      true    // refout
-  );
-}
-
 std::span<uint8_t> inner(const std::span<uint8_t> &buffer, Light::Id id, const std::span<uint8_t> &light_data) {
     if (id.kind() != 'L')
 	return {};
@@ -169,13 +158,17 @@ std::span<uint8_t> payload(const std::span<uint8_t> &buffer, const Key &key, Lig
     if (result.empty())
         return {};
 
+    const auto crc_guarded = subspan(buffer, prefix.size(), address.size() + command.size());
+    if (crc_guarded.empty())
+	return {};
+
     // static values
     std::copy(PREFIX.cbegin(), PREFIX.cend(), prefix.begin());
 
     // copy
     std::copy(ADDRESS.cbegin(), ADDRESS.cend(), address.begin());
 
-    uint16_t crc_value = crc16(buffer.subspan(prefix.size(), address.size() + command.size()));
+    uint16_t crc_value = ~crc16(&crc_guarded[0], crc_guarded.size(), 0xFFFF, true, true);
     crc[0] = crc_value;
     crc[1] = crc_value >> 8;