From cb73d4b3de91c9b6fc133e5b6bf6450c55c108ba Mon Sep 17 00:00:00 2001
From: Frank <91616163+softhack007@users.noreply.github.com>
Date: Mon, 12 Jan 2026 19:18:50 +0100
Subject: [PATCH] robustness improvement

---
 wled00/bus_manager.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/wled00/bus_manager.cpp b/wled00/bus_manager.cpp
index 1f75410e..8e43f684 100644
--- a/wled00/bus_manager.cpp
+++ b/wled00/bus_manager.cpp
@@ -1293,10 +1293,11 @@ int BusManager::add(BusConfig &bc) {
     busses[numBusses] = new BusPwm(bc);
   }
 
-  // WLEDMM ToDO
   Bus *newBus = busses[numBusses];
+  if (newBus == nullptr) return numBusses; // WLEDMM early exit if bus creation failed
+
   unsigned newStart = newBus->getStart();
-  unsigned newEnd = newStart + newBus->getLength() - 1;
+  unsigned newEnd = newStart + max(newBus->getLength() - 1, 0); // "max" needed for single-pixel busses
   // WLEDMM check if added bus overlaps with any existing bus
   bool foundOverlap = false;
   unsigned busCount = getNumBusses();