Fix re-init segment data leak (fixes #2535 ) (#2536)

wled00/FX.h

@@ -81,7 +81,6 @@
 #define SEGLEN           _virtualSegmentLength
 #define SEGACT           SEGMENT.stop
 #define SPEED_FORMULA_L  5U + (50U*(255U - SEGMENT.speed))/SEGLEN
-#define RESET_RUNTIME    memset(_segment_runtimes, 0, sizeof(_segment_runtimes))
 
 // some common colors
 #define RED        (uint32_t)0xFF0000
@@ -409,8 +408,9 @@ class WS2812FX {
        * Flags that before the next effect is calculated,
        * the internal segment state should be reset. 
        * Call resetIfRequired before calling the next effect function.
+       * Safe to call from interrupts and network requests.
        */
-      inline void reset() { _requiresReset = true; }
+      inline void markForReset() { _requiresReset = true; }
       private:
         uint16_t _dataLen = 0;
         bool _requiresReset = false;

wled00/FX_fcn.cpp

@@ -67,7 +67,12 @@
 //do not call this method from system context (network callback)
 void WS2812FX::finalizeInit(void)
 {
-  RESET_RUNTIME;
+  //reset segment runtimes
+  for (uint8_t i = 0; i < MAX_NUM_SEGMENTS; i++) {
+    _segment_runtimes[i].markForReset();
+    _segment_runtimes[i].resetIfRequired();
+  }
+
   _hasWhiteChannel = _isOffRefreshRequired = false;
 
   //if busses failed to load, add default (fresh install, FS issue, ...)
@@ -373,7 +378,7 @@ void WS2812FX::setMode(uint8_t segid, uint8_t m) {
 
   if (_segments[segid].mode != m) 
   {
-    _segment_runtimes[segid].reset();
+    _segment_runtimes[segid].markForReset();
     _segments[segid].mode = m;
   }
 }
@@ -612,12 +617,12 @@ void WS2812FX::setSegment(uint8_t n, uint16_t i1, uint16_t i2, uint8_t grouping,
     seg.spacing = spacing;
   }
 	if (offset < UINT16_MAX) seg.offset = offset;
-  _segment_runtimes[n].reset();
+  _segment_runtimes[n].markForReset();
 }
 
 void WS2812FX::restartRuntime() {
   for (uint8_t i = 0; i < MAX_NUM_SEGMENTS; i++) {
-    _segment_runtimes[i].reset();
+    _segment_runtimes[i].markForReset();
   }
 }
 
@@ -648,9 +653,9 @@ void WS2812FX::resetSegments() {
     _segments[i].cct = 127;
     _segments[i].speed = DEFAULT_SPEED;
     _segments[i].intensity = DEFAULT_INTENSITY;
-    _segment_runtimes[i].reset();
+    _segment_runtimes[i].markForReset();
   }
-  _segment_runtimes[0].reset();
+  _segment_runtimes[0].markForReset();
 }
 
 void WS2812FX::makeAutoSegments() {