From 91dc9a5b5a3d3908c36a71a5fa82939e850d700b Mon Sep 17 00:00:00 2001
From: Frank <91616163+softhack007@users.noreply.github.com>
Date: Mon, 29 Dec 2025 21:09:04 +0100
Subject: [PATCH] restore revious presetToSave in case that mutex acquisition
 fails

---
 wled00/presets.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/wled00/presets.cpp b/wled00/presets.cpp
index 2ef0bfd7..996aff3b 100644
--- a/wled00/presets.cpp
+++ b/wled00/presets.cpp
@@ -312,6 +312,7 @@ void savePreset(byte index, const char* pname, JsonObject sObj)
   }
 
   DEBUG_PRINT(F("Saving preset (")); DEBUG_PRINT(index); DEBUG_PRINT(F(") ")); DEBUG_PRINTLN(saveName);
+  auto oldpresetToSave = presetToSave; // for recovery in case that esp32SemTake(presetFileMux) fails
 
   presetToSave = index;
   playlistSave = false;
@@ -330,6 +331,7 @@ void savePreset(byte index, const char* pname, JsonObject sObj)
       // WLEDMM Acquire file mutex before writing presets.json, to prevent presets.json corruption
       if (esp32SemTake(presetFileMux, 2500) != pdTRUE) {
           USER_PRINTLN(F("savePreset(): preset file busy, cannot write"));
+          presetToSave = oldpresetToSave;
           return; // early exit, no change
       }