Fix many missing NULLs (#1389)

* Fix many missing NULLs

* Fix a raw actor id in en_horse

src/code/audio_data.c

@@ -553,7 +553,7 @@ EnvelopePoint gDefaultEnvelope[] = {
 NoteSubEu gZeroNoteSub = { 0 };
 
 NoteSubEu gDefaultNoteSub = {
-    { 1, 1, 0, 0, 0, 0, 0, 0 }, { 0 }, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    { 1, 1, 0, 0, 0, 0, 0, 0 }, { 0 }, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, NULL, NULL, 0,
 };
 
 u16 gHaasEffectDelaySizes[64] = {

src/code/audio_synthesis.c

@@ -1085,7 +1085,7 @@ Acmd* AudioSynth_ProcessNote(s32 noteIndex, NoteSubEu* noteSubEu, NoteSynthesisS
     }
 
     filter = noteSubEu->filter;
-    if (filter != 0) {
+    if (filter != NULL) {
         AudioSynth_LoadFilterSize(cmd++, aiBufLen * SAMPLE_SIZE, filter);
         AudioSynth_LoadFilterBuffer(cmd++, flags, DMEM_TEMP, synthState->synthesisBuffers->mixEnvelopeState);
     }

src/code/code_800EC960.c

@@ -3071,7 +3071,7 @@ void AudioDebug_Draw(GfxPrint* printer) {
             }
 
             GfxPrint_SetPos(printer, 3, 24);
-            if (sSariaBgmPtr != 0) {
+            if (sSariaBgmPtr != NULL) {
                 GfxPrint_Printf(printer, "SARIA BGM PTR %08x", sSariaBgmPtr);
             }
 

src/code/code_800FC620.c

@@ -73,10 +73,10 @@ void func_800FCA18(void* blk, u32 nBlk, u32 blkSize, arg3_800FCA18 arg3, s32 arg
     u32 pos;
     u32 end;
 
-    if (blk == 0) {
+    if (blk == NULL) {
         return;
     }
-    if (arg3 != 0) {
+    if (arg3 != NULL) {
         end = (u32)blk;
         pos = (u32)end + (nBlk * blkSize);
 

src/code/fault.c

@@ -1272,7 +1272,7 @@ void Fault_Init(void) {
     gFaultMgr.faultHandlerEnabled = true;
     osCreateMesgQueue(&sFaultInstance->queue, &sFaultInstance->msg, 1);
     StackCheck_Init(&sFaultThreadInfo, sFaultStack, STACK_TOP(sFaultStack), 0, 0x100, "fault");
-    osCreateThread(&sFaultInstance->thread, THREAD_ID_FAULT, Fault_ThreadEntry, 0, STACK_TOP(sFaultStack),
+    osCreateThread(&sFaultInstance->thread, THREAD_ID_FAULT, Fault_ThreadEntry, NULL, STACK_TOP(sFaultStack),
                    THREAD_PRI_FAULT);
     osStartThread(&sFaultInstance->thread);
 }

src/code/z_DLF.c

@@ -7,7 +7,7 @@ void Overlay_LoadGameState(GameStateOverlay* overlayEntry) {
         return;
     }
 
-    if (overlayEntry->vramStart == 0) {
+    if (overlayEntry->vramStart == NULL) {
         overlayEntry->unk_28 = 0;
     } else {
         overlayEntry->loadedRamAddr = Overlay_AllocateAndLoad(overlayEntry->vromStart, overlayEntry->vromEnd,

src/code/z_actor.c

@@ -2682,7 +2682,7 @@ Actor* Actor_Spawn(ActorContext* actorCtx, PlayState* play, s16 actorId, f32 pos
         return NULL;
     }
 
-    if (overlayEntry->vramStart == 0) {
+    if (overlayEntry->vramStart == NULL) {
         if (HREG(20) != 0) {
             osSyncPrintf("オーバーレイではありません\n"); // "Not an overlay"
         }
@@ -2894,7 +2894,7 @@ Actor* Actor_Delete(ActorContext* actorCtx, Actor* actor, PlayState* play) {
 
     ZeldaArena_FreeDebug(actor, "../z_actor.c", 7242);
 
-    if (overlayEntry->vramStart == 0) {
+    if (overlayEntry->vramStart == NULL) {
         if (HREG(20) != 0) {
             osSyncPrintf("オーバーレイではありません\n"); // "Not an overlay"
         }
@@ -3001,7 +3001,7 @@ Actor* func_80032AF0(PlayState* play, ActorContext* actorCtx, Actor** actorPtr,
         }
     }
 
-    if (D_8015BBE8 == 0) {
+    if (D_8015BBE8 == NULL) {
         *actorPtr = D_8015BBEC;
     } else {
         *actorPtr = D_8015BBE8;

src/code/z_collision_check.c

@@ -680,7 +680,7 @@ s32 Collider_ResetTrisElementOC(PlayState* play, ColliderTrisElement* element) {
 s32 Collider_InitTris(PlayState* play, ColliderTris* tris) {
     Collider_InitBase(play, &tris->base);
     tris->count = 0;
-    tris->elements = 0;
+    tris->elements = NULL;
     return true;
 }
 

src/code/z_kaleido_manager.c

@@ -64,7 +64,7 @@ void KaleidoManager_Init(PlayState* play) {
     osSyncPrintf("KaleidoArea %08x - %08x\n", sKaleidoAreaPtr, (u32)sKaleidoAreaPtr + largestSize);
     osSyncPrintf(VT_RST);
 
-    gKaleidoMgrCurOvl = 0;
+    gKaleidoMgrCurOvl = NULL;
 }
 
 void KaleidoManager_Destroy(void) {

src/code/z_play.c

@@ -175,7 +175,7 @@ void Play_Destroy(GameState* thisx) {
     Player* player = GET_PLAYER(this);
 
     this->state.gfxCtx->callback = NULL;
-    this->state.gfxCtx->callbackParam = 0;
+    this->state.gfxCtx->callbackParam = NULL;
 
     SREG(91) = 0;
     R_PAUSE_MENU_MODE = 0;

src/code/z_skelanime.c

@@ -208,7 +208,7 @@ void SkelAnime_DrawFlexLod(PlayState* play, void** skeleton, Vec3s* jointTable,
 
     newDList = limbDList = rootLimb->dLists[lod];
 
-    if ((overrideLimbDraw == 0) || !overrideLimbDraw(play, 1, &newDList, &pos, &rot, arg)) {
+    if ((overrideLimbDraw == NULL) || !overrideLimbDraw(play, 1, &newDList, &pos, &rot, arg)) {
         Matrix_TranslateRotateZYX(&pos, &rot);
         if (newDList != NULL) {
             Matrix_ToMtx(mtx, "../z_skelanime.c", 1033);