From 6247ee066dd912f9e88b7914bb3d956936967c69 Mon Sep 17 00:00:00 2001
From: Frank <91616163+softhack007@users.noreply.github.com>
Date: Mon, 29 Dec 2025 20:08:34 +0100
Subject: [PATCH] fix presets.json corruption, part 1: avoid re-assigning open
 file pointer

* this prevents "open after open", that could lead to file corruption when "f" was still holding some changes in its buffer (written out with f.close())
---
 wled00/file.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/wled00/file.cpp b/wled00/file.cpp
index bb853df9..bf8ef929 100644
--- a/wled00/file.cpp
+++ b/wled00/file.cpp
@@ -299,6 +299,11 @@ bool writeObjectToFile(const char* file, const char* key, JsonDocument* content)
     s = millis();
   #endif
 
+  if (doCloseFile) {
+    if (f) { DEBUG_PRINTLN("writeObjectToFile("+String(file)+"): file f is already open, closing to prevent file corruption."); }
+    closeFile();  // WLEDMM: Ensure previous file is closed
+  }
+
   size_t pos = 0;
   f = WLED_FS.open(file, "r+");
   if (!f && !WLED_FS.exists(file)) { f = WLED_FS.open(file, "w+");