From 3295579e054761fa6a08f60f552a17637491b44d Mon Sep 17 00:00:00 2001
From: Frank <91616163+softhack007@users.noreply.github.com>
Date: Thu, 13 Jul 2023 18:36:11 +0200
Subject: [PATCH] jsonToPixels robustness

avoid string overflow when constructing filename
---
 wled00/FX_2Dfcn.cpp | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/wled00/FX_2Dfcn.cpp b/wled00/FX_2Dfcn.cpp
index 6dfc77b3..0556935c 100644
--- a/wled00/FX_2Dfcn.cpp
+++ b/wled00/FX_2Dfcn.cpp
@@ -605,11 +605,12 @@ void Segment::drawArc(uint16_t x0, uint16_t y0, uint16_t radius, uint32_t color,
 
 //WLEDMM for artifx
 bool Segment::jsonToPixels(char * name, uint8_t fileNr) {
-  char fileName[32];
+  if (!isActive()) return true; // segment not active, nothing to do
+  char fileName[32] = { '\0' };
   //WLEDMM: als support segment name ledmaps
-  bool isFile = false;;
+  bool isFile = false;
   // strcpy_P(fileName, PSTR("/mario"));
-  sprintf(fileName, "/%s%d.json", name, fileNr); //WLEDMM: trick to not include 0 in ledmap.json
+  snprintf(fileName, sizeof(fileName), "/%s%d.json", name, fileNr); //WLEDMM: trick to not include 0 in ledmap.json
   // strcat(fileName, ".json");
   isFile = WLED_FS.exists(fileName);