From c35e3747399ef9688f6bb258a127c5a3b5ed678e Mon Sep 17 00:00:00 2001
From: Theo Arends <11044339+arendst@users.noreply.github.com>
Date: Mon, 15 Dec 2025 11:26:38 +0100
Subject: [PATCH] Fix ESP8266 TasmotaSerial flush receive buffer on executing
 `TasmotaSerial.flush();`

---
 CHANGELOG.md                                          | 1 +
 RELEASENOTES.md                                       | 1 +
 lib/default/TasmotaSerial-3.7.0/src/TasmotaSerial.cpp | 7 ++++---
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 238789610..12c820c43 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ All notable changes to this project will be documented in this file.
 ### Fixed
 - DALI watchdog exception
 - TuyaMCU v1 exception 28 regression from v15.1.0.1 reverted PR24063 (#24220)
+- ESP8266 TasmotaSerial flush receive buffer on executing `TasmotaSerial.flush();`
 
 ### Removed
 
diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 6932798b3..5371121d7 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -119,5 +119,6 @@ The latter links can be used for OTA upgrades too like ``OtaUrl https://ota.tasm
 - Vid6608 library from v1.0.2 to v1.0.3 [#24218](https://github.com/arendst/Tasmota/issues/24218)
 
 ### Fixed
+- ESP8266 TasmotaSerial flush receive buffer on executing `TasmotaSerial.flush();`
 - DALI watchdog exception
 - TuyaMCU v1 exception 28 regression from v15.1.0.1 reverted PR24063 [#24220](https://github.com/arendst/Tasmota/issues/24220)
diff --git a/lib/default/TasmotaSerial-3.7.0/src/TasmotaSerial.cpp b/lib/default/TasmotaSerial-3.7.0/src/TasmotaSerial.cpp
index 3b0441e1c..7d67faa10 100644
--- a/lib/default/TasmotaSerial-3.7.0/src/TasmotaSerial.cpp
+++ b/lib/default/TasmotaSerial-3.7.0/src/TasmotaSerial.cpp
@@ -353,14 +353,15 @@ bool TasmotaSerial::overflow(void) {
 void TasmotaSerial::flush(void) {
   if (m_hardserial) {
 #ifdef ESP8266
-    Serial.flush();
+    Serial.flush();    // Flushes Tx only
+    while (Serial.available()) { Serial.read(); }  // Flushes Rx
 #endif  // ESP8266
 #ifdef ESP32
     TSerial->flush();  // Flushes Tx only https://github.com/espressif/arduino-esp32/pull/4263
-    while (TSerial->available()) { TSerial->read(); }
+    while (TSerial->available()) { TSerial->read(); }  // Flushes Rx
 #endif  // ESP32
   } else {
-    m_in_pos = 0;
+    m_in_pos = 0;      // Flushes Rx, Tx is always flushed
     m_out_pos = 0;
   }
 }