From cb654a1e503c3e3554213290c25430255e5eac7d Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Sat, 11 Apr 2026 22:58:13 -1000
Subject: [PATCH] [esp8266] Handle delay(0) as a yield point
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Arduino's delay(0) calls yield() once — used as a yield point by some
code. Our millis-based loop would skip yielding entirely since
0 < 0 is false. Add explicit delay(0) → yield() handling.
---
 esphome/components/esp8266/core.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/esphome/components/esp8266/core.cpp b/esphome/components/esp8266/core.cpp
index 68ca8a903b..32dd097c8d 100644
--- a/esphome/components/esp8266/core.cpp
+++ b/esphome/components/esp8266/core.cpp
@@ -60,9 +60,13 @@ uint64_t millis_64() { return Millis64Impl::compute(millis()); }
 // original millis body (~80 bytes IRAM). This yield loop achieves the same
 // behavior: feeds the watchdog, processes SDK tasks, keeps WiFi alive.
 void HOT delay(uint32_t ms) {
+  if (ms == 0) {
+    optimistic_yield(1000);
+    return;
+  }
   uint32_t start = millis();
   while (millis() - start < ms) {
-    yield();
+    optimistic_yield(1000);
   }
 }
 uint32_t IRAM_ATTR HOT micros() { return ::micros(); }