From 0745eaf2e07873639778fb29258fefe157070980 Mon Sep 17 00:00:00 2001
From: Ariel A <24759293+aarant@users.noreply.github.com>
Date: Mon, 12 Aug 2024 22:42:31 -0400
Subject: [PATCH] fix: Uninitialized value used in  `LightenSpritePaletteInFog`

---
 include/palette.h   |  7 +++++++
 src/field_weather.c |  6 +++---
 src/overworld.c     | 14 ++++++--------
 src/palette.c       |  6 +++---
 4 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/include/palette.h b/include/palette.h
index fa41b2d0db..930499b877 100644
--- a/include/palette.h
+++ b/include/palette.h
@@ -14,6 +14,8 @@
 #define PALETTE_FADE_STATUS_LOADING 0xFF
 
 #define PALETTES_BG      0x0000FFFF
+// like PALETTES_BG but excludes UI pals [13, 15]
+#define PALETTES_MAP     0x00001FFF
 #define PALETTES_OBJECTS 0xFFFF0000
 #define PALETTES_ALL     (PALETTES_BG | PALETTES_OBJECTS)
 
@@ -24,6 +26,11 @@
 #define OBJ_PLTT_ID(n) (OBJ_PLTT_OFFSET + PLTT_ID(n))
 #define OBJ_PLTT_ID2(n) (PLTT_ID((n) + 16))
 
+// Used to determine whether a sprite palette tag
+// should be excluded from time (and weather) blending
+#define BLEND_IMMUNE_FLAG (1 << 15)
+#define IS_BLEND_IMMUNE_TAG(tag) ((tag) & BLEND_IMMUNE_FLAG)
+
 enum
 {
     FAST_FADE_IN_FROM_WHITE,
diff --git a/src/field_weather.c b/src/field_weather.c
index bd15ad0742..1a3a150c4c 100644
--- a/src/field_weather.c
+++ b/src/field_weather.c
@@ -495,7 +495,7 @@ static void ApplyColorMap(u8 startPalIndex, u8 numPalettes, s8 colorMapIndex)
         {
             // don't blend special palettes immune to blending
             if (sPaletteColorMapTypes[curPalIndex] == COLOR_MAP_NONE ||
-                (curPalIndex >= 16 && GetSpritePaletteTagByPaletteNum(curPalIndex - 16) >> 15))
+                (curPalIndex >= 16 && IS_BLEND_IMMUNE_TAG(GetSpritePaletteTagByPaletteNum(curPalIndex - 16))))
             {
                 // No palette change.
                 palOffset += 16;
@@ -684,7 +684,7 @@ static void ApplyFogBlend(u8 blendCoeff, u16 blendColor)
     CpuFastCopy(gPlttBufferUnfaded, gPlttBufferFaded, PLTT_BUFFER_SIZE * 2);
     UpdatePalettesWithTime(PALETTES_ALL);
     // Then blend tile palettes [0, 12] faded->faded with fadeIn color
-    BlendPalettesFine(0x1FFF, gPlttBufferFaded, gPlttBufferFaded, blendCoeff, blendColor);
+    BlendPalettesFine(PALETTES_MAP, gPlttBufferFaded, gPlttBufferFaded, blendCoeff, blendColor);
 
     // Do fog blending on marked sprite palettes
     for (curPalIndex = 16; curPalIndex < 32; curPalIndex++) {
@@ -708,7 +708,7 @@ static bool8 LightenSpritePaletteInFog(u8 paletteIndex)
 {
     u16 i;
 
-    if (paletteIndex >= 16 && (GetSpritePaletteTagByPaletteNum(i - 16) >> 15)) // don't blend specialpalette tags
+    if (paletteIndex >= 16 && IS_BLEND_IMMUNE_TAG(GetSpritePaletteTagByPaletteNum(paletteIndex - 16)))
         return FALSE;
 
     for (i = 0; i < gWeatherPtr->lightenedFogSpritePalsCount; i++)
diff --git a/src/overworld.c b/src/overworld.c
index 7a39a2a6ba..9c4bd0cdfb 100644
--- a/src/overworld.c
+++ b/src/overworld.c
@@ -1536,7 +1536,7 @@ void UpdateAltBgPalettes(u16 palettes) {
         return;
     palettes &= ~((1 << NUM_PALS_IN_PRIMARY) - 1) | primary->swapPalettes;
     palettes &= ((1 << NUM_PALS_IN_PRIMARY) - 1) | (secondary->swapPalettes << NUM_PALS_IN_PRIMARY);
-    palettes &= 0x1FFE; // don't blend palette 0, [13,15]
+    palettes &= PALETTES_MAP ^ (1 << 0); // don't blend palette 0, [13,15]
     palettes >>= 1; // start at palette 1
     if (!palettes)
         return;
@@ -1558,10 +1558,10 @@ void UpdatePalettesWithTime(u32 palettes) {
     u32 mask = 1 << 16;
     if (palettes >= 0x10000)
       for (i = 0; i < 16; i++, mask <<= 1)
-        if (GetSpritePaletteTagByPaletteNum(i) >> 15) // Don't blend special sprite palette tags
+        if (IS_BLEND_IMMUNE_TAG(GetSpritePaletteTagByPaletteNum(i)))
           palettes &= ~(mask);
 
-    palettes &= 0xFFFF1FFF; // Don't blend UI BG palettes [13,15]
+    palettes &= PALETTES_MAP | PALETTES_OBJECTS; // Don't blend UI pals
     if (!palettes)
       return;
     TimeMixPalettes(palettes,
@@ -1575,13 +1575,11 @@ void UpdatePalettesWithTime(u32 palettes) {
 
 u8 UpdateSpritePaletteWithTime(u8 paletteNum) {
   if (MapHasNaturalLight(gMapHeader.mapType)) {
-    u16 offset;
-    if (GetSpritePaletteTagByPaletteNum(paletteNum) >> 15)
+    if (IS_BLEND_IMMUNE_TAG(GetSpritePaletteTagByPaletteNum(paletteNum)))
       return paletteNum;
-    offset = (paletteNum + 16) << 4;
     TimeMixPalettes(1,
-      gPlttBufferUnfaded + offset,
-      gPlttBufferFaded + offset,
+      &gPlttBufferUnfaded[OBJ_PLTT_ID(paletteNum)],
+      &gPlttBufferFaded[OBJ_PLTT_ID(paletteNum)],
       (struct BlendSettings *)&gTimeOfDayBlend[currentTimeBlend.time0],
       (struct BlendSettings *)&gTimeOfDayBlend[currentTimeBlend.time1],
       currentTimeBlend.weight);
diff --git a/src/palette.c b/src/palette.c
index 0093a4bf69..a8be1867a7 100644
--- a/src/palette.c
+++ b/src/palette.c
@@ -515,11 +515,11 @@ static u8 UpdateTimeOfDayPaletteFade(void)
         u32 i;
         u32 j = 1;
         for (i = 0; i < 16; i++, j <<= 1) { // Mask out palettes that should not be light blended
-            if ((selectedPalettes & j) && !(GetSpritePaletteTagByPaletteNum(i) >> 15))
-            timePalettes |= j;
+            if ((selectedPalettes & j) && !IS_BLEND_IMMUNE_TAG(GetSpritePaletteTagByPaletteNum(i)))
+                timePalettes |= j;
         }
     } else { // tile palettes, don't blend [13, 15]
-        timePalettes = selectedPalettes & 0x1FFF;
+        timePalettes = selectedPalettes & PALETTES_MAP;
     }
     TimeMixPalettes(timePalettes, src, dst, gPaletteFade.bld0, gPaletteFade.bld1, gPaletteFade.weight);