From 16e96dfbc00dfad229c3e635561f61fb9c88de70 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Fri, 26 Dec 2025 20:18:25 -1000
Subject: [PATCH] fixes

---
 esphome/components/ota/ota_backend_esp8266.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/esphome/components/ota/ota_backend_esp8266.cpp b/esphome/components/ota/ota_backend_esp8266.cpp
index 03163c6f51..b450babd38 100644
--- a/esphome/components/ota/ota_backend_esp8266.cpp
+++ b/esphome/components/ota/ota_backend_esp8266.cpp
@@ -249,6 +249,13 @@ OTAResponseTypes ESP8266OTABackend::end() {
   // Calculate actual bytes written
   size_t actual_size = this->current_address_ - this->start_address_;
 
+  // Check if any data was written
+  if (actual_size == 0) {
+    ESP_LOGE(TAG, "No data written");
+    this->abort();
+    return OTA_RESPONSE_ERROR_UPDATE_END;
+  }
+
   // Verify MD5 if set (strict mode), otherwise use lenient mode
   // In lenient mode (no MD5), we accept whatever was written
   if (this->md5_set_) {