From 7eb81ae01eb1c19006fb2adb275577d8e798a897 Mon Sep 17 00:00:00 2001
From: Johan Schuld <johan.schuld@resideo.com>
Date: Mon, 7 Sep 2026 13:42:30 +1200
Subject: [PATCH 1/2]  Fixed issue when exactly 255 bytes (non zero) are
 encoded.

---
 components/cobs/example/main/cobs_example.cpp | 18 ++++++++++++++++++
 components/cobs/src/cobs.cpp                  |  3 +--
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/components/cobs/example/main/cobs_example.cpp b/components/cobs/example/main/cobs_example.cpp
index acf8c0391f..710b8cacb0 100644
--- a/components/cobs/example/main/cobs_example.cpp
+++ b/components/cobs/example/main/cobs_example.cpp
@@ -682,6 +682,24 @@ void test_edge_cases(espp::Logger &logger) {
           decoded.size(), large_packet.size(), encoded.size());
     }
   }
+
+  // Test 5: Packet of exactly block len with no zero's in the data
+  {
+    std::vector<uint8_t> block_len_packet(255, 0x42);
+
+    std::vector<uint8_t> encoded = Cobs::encode_packet(block_len_packet);
+    std::vector<uint8_t> decoded = Cobs::decode_packet(encoded);
+
+    bool success = (decoded.size() == block_len_packet.size()) &&
+                   (std::memcmp(decoded.data(), block_len_packet.data(), block_len_packet.size()) == 0);
+    if (success) {
+      logger.info("Test 5: PASS - Packet of exactly block len with no zeros");
+    } else {
+      logger.error(
+          "Test 5: FAIL - Packet of exactly block len with no zeros (decoded: {}, expected: {}, encoded: {})",
+          decoded.size(), block_len_packet.size(), encoded.size());
+    }
+  }  
 }
 
 extern "C" void app_main(void) {
diff --git a/components/cobs/src/cobs.cpp b/components/cobs/src/cobs.cpp
index 4eb848061a..9ae8ac33b2 100644
--- a/components/cobs/src/cobs.cpp
+++ b/components/cobs/src/cobs.cpp
@@ -44,8 +44,7 @@ size_t Cobs::encode_packet(std::span<const uint8_t> data, std::span<uint8_t> out
       *codep = code;
       code = 1;
       codep = encode;
-      if (!byte)
-        ++encode;
+      ++encode;
     }
   }
   *codep = code; // Write final code value

From bf0c025e254c3924f1e284b218d072750ac60743 Mon Sep 17 00:00:00 2001
From: Johan Schuld <johan.schuld@resideo.com>
Date: Mon, 7 Sep 2026 14:03:38 +1200
Subject: [PATCH 2/2] copilot  code review feedback.

---
 components/cobs/example/main/cobs_example.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/components/cobs/example/main/cobs_example.cpp b/components/cobs/example/main/cobs_example.cpp
index 710b8cacb0..e370173272 100644
--- a/components/cobs/example/main/cobs_example.cpp
+++ b/components/cobs/example/main/cobs_example.cpp
@@ -683,7 +683,7 @@ void test_edge_cases(espp::Logger &logger) {
     }
   }
 
-  // Test 5: Packet of exactly block len with no zero's in the data
+  // Test 5: Packet of exactly 255 bytes with no zeros in the data
   {
     std::vector<uint8_t> block_len_packet(255, 0x42);
 
@@ -693,13 +693,13 @@ void test_edge_cases(espp::Logger &logger) {
     bool success = (decoded.size() == block_len_packet.size()) &&
                    (std::memcmp(decoded.data(), block_len_packet.data(), block_len_packet.size()) == 0);
     if (success) {
-      logger.info("Test 5: PASS - Packet of exactly block len with no zeros");
+      logger.info("Test 5: PASS - Packet of exactly 255 bytes with no zeros");
     } else {
       logger.error(
-          "Test 5: FAIL - Packet of exactly block len with no zeros (decoded: {}, expected: {}, encoded: {})",
+          "Test 5: FAIL - Packet of exactly 255 bytes with no zeros (decoded: {}, expected: {}, encoded: {})",
           decoded.size(), block_len_packet.size(), encoded.size());
     }
-  }  
+  }
 }
 
 extern "C" void app_main(void) {