From 289120ee92e83df175076eb888c28f5e24871372 Mon Sep 17 00:00:00 2001
From: Theo Arends <11044339+arendst@users.noreply.github.com>
Date: Fri, 28 Mar 2025 12:16:32 +0100
Subject: [PATCH] Fix telnet buffer overrun detection

---
 CHANGELOG.md                                   | 2 +-
 RELEASENOTES.md                                | 3 ++-
 tasmota/tasmota_xdrv_driver/xdrv_78_telnet.ino | 8 +++++---
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2039ea9bf..e86b19504 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,7 +6,7 @@ All notable changes to this project will be documented in this file.
 ## [14.5.0.3] 
 ### Added
 - Extend command `GPIO` with different display options and allowing updating of module GPIO's in one go
-- Berry `bytes.add()` now accepts 3-bytes values
+- Berry `bytes.add()` now accepts 3-bytes values (#23200)
 
 ### Breaking Changed
 
diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 6d5a83564..4e56a01c1 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -126,7 +126,8 @@ The latter links can be used for OTA upgrades too like ``OtaUrl https://ota.tasm
 - Berry `introspect.solidified()` to know if a Berry object is solidified or in RAM [#23063](https://github.com/arendst/Tasmota/issues/23063)
 - Berry `global.undef()` to undefine a global variable [#23073](https://github.com/arendst/Tasmota/issues/23073)
 - Berry load `.tapp` files in `/.extensions/` then in `/` [#23113](https://github.com/arendst/Tasmota/issues/23113)
-- Berry `re.dump()` (#23162)[#23162](https://github.com/arendst/Tasmota/issues/23162)
+- Berry `re.dump()` [#23162](https://github.com/arendst/Tasmota/issues/23162)
+- Berry `bytes.add()` now accepts 3-bytes values [#23200](https://github.com/arendst/Tasmota/issues/23200)
 - Matter prepare for ICD cluster [#23158](https://github.com/arendst/Tasmota/issues/23158)
 - LVGL experimental mirroring of display on Web UI [#23041](https://github.com/arendst/Tasmota/issues/23041)
 - HASPmota autostart when `pages.jsonl` exists [#23181](https://github.com/arendst/Tasmota/issues/23181)
diff --git a/tasmota/tasmota_xdrv_driver/xdrv_78_telnet.ino b/tasmota/tasmota_xdrv_driver/xdrv_78_telnet.ino
index cf38bdc80..a6620d3b0 100644
--- a/tasmota/tasmota_xdrv_driver/xdrv_78_telnet.ino
+++ b/tasmota/tasmota_xdrv_driver/xdrv_78_telnet.ino
@@ -86,6 +86,7 @@ struct {
   uint8_t     color[3];
   bool        ip_filter_enabled;
   bool        color_disable;
+  bool        overrun;
 } Telnet;
 
 /********************************************************************************************/
@@ -126,9 +127,7 @@ void TelnetGetLog(void) {
   uint32_t index = Telnet.log_index;                 // Dump log buffer
   char* line;
   size_t len;
-  bool any_line = false;
   while (GetLog(TasmotaGlobal.seriallog_level, &index, &line, &len)) {
-    any_line = true;
     TelnetWrite(line, len -1);
   }
   Telnet.log_index = index;
@@ -185,6 +184,8 @@ void TelnetLoop(void) {
       if (isprint(in_byte)) {                        // Any char between 32 and 127
         if (Telnet.in_byte_counter < Telnet.buffer_size -1) {  // Add char to string if it still fits
           Telnet.buffer[Telnet.in_byte_counter++] = in_byte;
+        } else {
+          Telnet.overrun = true;
         }
       }
       else if (in_byte == '\n') {
@@ -192,7 +193,7 @@ void TelnetLoop(void) {
         Telnet.buffer[Telnet.in_byte_counter] = 0;   // Telnet data completed
         Telnet.prompt = 1;                           // Print prompt after requested data and use response color
         SetMinimumSeriallog();
-        if (Telnet.in_byte_counter >= Telnet.buffer_size) {
+        if (Telnet.overrun) {
           AddLog(LOG_LEVEL_INFO, PSTR(D_LOG_TELNET "Buffer overrun"));
         } else {
           char command[CMDSZ];
@@ -205,6 +206,7 @@ void TelnetLoop(void) {
           }
         }
         Telnet.in_byte_counter = 0;
+        Telnet.overrun = false;
         return;
       }
     }