From d78ea5ae2edd5a4fb03b8ad9947b0b1c64d7165f Mon Sep 17 00:00:00 2001
From: Frank <91616163+softhack007@users.noreply.github.com>
Date: Fri, 7 Nov 2025 15:07:13 +0100
Subject: [PATCH] prevent bad filenames in "segment names as ledmap names"

Increase buffer size for fileName to accommodate long segment names (max 32 chars) without producing broken filenames.
---
 wled00/FX_fcn.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/wled00/FX_fcn.cpp b/wled00/FX_fcn.cpp
index 34b77f1f..5847309e 100644
--- a/wled00/FX_fcn.cpp
+++ b/wled00/FX_fcn.cpp
@@ -1765,8 +1765,8 @@ void WS2812FX::enumerateLedmaps() {
   uint8_t segment_index = 0;
   for (segment &seg : _segments) {
     if (seg.name != nullptr && strlen(seg.name) > 0) {
-      char fileName[33];
-      snprintf_P(fileName, sizeof(fileName), PSTR("/lm%s.json"), seg.name);
+      char fileName[33+11] = { '\0' }; // segment name is 32 chars max, so we need 43 chars in worst case
+      snprintf_P(fileName, sizeof(fileName)-1, PSTR("/lm%s.json"), seg.name);
       bool isFile = WLED_FS.exists(fileName);
       if (isFile) ledMaps |= 1 << (10+segment_index);
     }