Fix Android Waveform Dropout: Implement Deep Copy for TrackState and add NULL pointer safety checks

Author: rayocta303

src/core/logic/quantize.c

@@ -3,7 +3,7 @@
 #include <math.h>
 
 int64_t Quantize_GetNearestBeatMs(TrackState *track, int64_t currentMs) {
-    if (!track || track->BeatGridCount == 0) return currentMs;
+    if (!track || track->BeatGridCount == 0 || !track->BeatGrid) return currentMs;
 
     // Find closest beat in BeatGrid array
     int64_t closestBeatMs = (int64_t)track->BeatGrid[0].Time;
@@ -24,13 +24,13 @@ int64_t Quantize_GetNearestBeatMs(TrackState *track, int64_t currentMs) {
 }
 
 int32_t Quantize_GetPhaseErrorMs(TrackState *track, int64_t currentMs) {
-    if (!track || track->BeatGridCount == 0) return 0;
+    if (!track || track->BeatGridCount == 0 || !track->BeatGrid) return 0;
     int64_t nearest = Quantize_GetNearestBeatMs(track, currentMs);
     return (int32_t)(currentMs - nearest);
 }
 
 int32_t Quantize_GetWaitMs(TrackState *track, int64_t currentMs) {
-    if (!track || track->BeatGridCount == 0) return 0;
+    if (!track || track->BeatGridCount == 0 || !track->BeatGrid) return 0;
 
     // Look forward for the *next* or *current* beat grid marker
     for (int i = 0; i < track->BeatGridCount; i++) {
@@ -42,7 +42,7 @@ int32_t Quantize_GetWaitMs(TrackState *track, int64_t currentMs) {
 }
 
 double Quantize_GetBeatDistance(TrackState *track, int64_t currentMs) {
-    if (!track || track->BeatGridCount < 2) return 0.0;
+    if (!track || track->BeatGridCount < 2 || !track->BeatGrid) return 0.0;
 
     for (int i = 0; i < track->BeatGridCount - 1; i++) {
         if (currentMs >= (int64_t)track->BeatGrid[i].Time && currentMs < (int64_t)track->BeatGrid[i+1].Time) {
@@ -57,7 +57,7 @@ double Quantize_GetBeatDistance(TrackState *track, int64_t currentMs) {
 }
 
 int Quantize_GetCurrentBeat(TrackState *track, int64_t currentMs) {
-    if (!track || track->BeatGridCount == 0) return 1;
+    if (!track || track->BeatGridCount == 0 || !track->BeatGrid) return 1;
     for (int i = 0; i < track->BeatGridCount; i++) {
         if ((int64_t)track->BeatGrid[i].Time > currentMs) {
             if (i == 0) return track->BeatGrid[0].BeatNumber;
@@ -68,7 +68,7 @@ int Quantize_GetCurrentBeat(TrackState *track, int64_t currentMs) {
 }
 
 float Quantize_GetBeatFXLengthMs(TrackState *track, float targetRatio) {
-    if (!track || track->BeatGridCount < 2) return 0.0f;
+    if (!track || track->BeatGridCount < 2 || !track->BeatGrid) return 0.0f;
 
     // Calculate average ms per beat from the grid
     int count = track->BeatGridCount;

src/ui/browser/browser.c

@@ -1082,15 +1082,26 @@ static int Browser_Update(Component *base) {
               newTrack->StaticWaveformType = t->StaticWaveformType;
               memcpy(newTrack->StaticWaveform, t->StaticWaveform,
                      t->StaticWaveformLen > 8192 ? 8192 : t->StaticWaveformLen);
-              newTrack->DynamicWaveform = t->DynamicWaveform;
+              
+              // DEEP COPY: Isolate dynamic waveform memory per deck
               newTrack->DynamicWaveformLen = t->DynamicWaveformLen;
+              if (newTrack->DynamicWaveformLen > 0 && t->DynamicWaveform != NULL) {
+                  newTrack->DynamicWaveform = (unsigned char*)malloc(newTrack->DynamicWaveformLen);
+                  if (newTrack->DynamicWaveform) {
+                      memcpy(newTrack->DynamicWaveform, t->DynamicWaveform, newTrack->DynamicWaveformLen);
+                  }
+              } else {
+                  newTrack->DynamicWaveform = NULL;
+              }
               newTrack->WaveformType = t->WaveformType;
 
               // Cues and Beats
               newTrack->BeatGridCount = t->BeatGridCount;
-              if (newTrack->BeatGridCount > 0) {
+              if (newTrack->BeatGridCount > 0 && t->BeatGrid != NULL) {
                   newTrack->BeatGrid = (RBBeat*)malloc(sizeof(RBBeat) * newTrack->BeatGridCount);
-                  memcpy(newTrack->BeatGrid, t->BeatGrid, sizeof(RBBeat) * newTrack->BeatGridCount);
+                  if (newTrack->BeatGrid) {
+                      memcpy(newTrack->BeatGrid, t->BeatGrid, sizeof(RBBeat) * newTrack->BeatGridCount);
+                  }
               } else {
                   newTrack->BeatGrid = NULL;
               }
@@ -1112,9 +1123,12 @@ static int Browser_Update(Component *base) {
               }
 
               TrackState *oldTrack = targetDeck->LoadedTrack;
-              targetDeck->LoadedTrack = newTrack;
+              targetDeck->LoadedTrack = newTrack; // Atomic pointer swap on UI thread
+
+              // Cleanup old track memory (including buffers)
               if (oldTrack){
                 if (oldTrack->BeatGrid != NULL) free(oldTrack->BeatGrid);
+                if (oldTrack->DynamicWaveform != NULL) free(oldTrack->DynamicWaveform);
                 free(oldTrack);
               }
 
@@ -1202,8 +1216,11 @@ static int Browser_Update(Component *base) {
 
               TrackState *oldTrack = targetDeck->LoadedTrack;
               targetDeck->LoadedTrack = newTrack;
-              if (oldTrack)
+              if (oldTrack) {
+                if (oldTrack->BeatGrid != NULL) free(oldTrack->BeatGrid);
+                if (oldTrack->DynamicWaveform != NULL) free(oldTrack->DynamicWaveform);
                 free(oldTrack);
+              }
               targetDeck->PositionMs =
                   (newTrack->CuesCount > 0) ? newTrack->Cues[0].Start : 0;
               DeckAudio_JumpToMs(&s->AudioPlugin->Decks[loadToDeck],