diff --git a/src/bsp/Bsp.cpp b/src/bsp/Bsp.cpp
index 077508d0..fb38b82f 100644
--- a/src/bsp/Bsp.cpp
+++ b/src/bsp/Bsp.cpp
@@ -1806,7 +1806,7 @@ unsigned int Bsp::remove_unused_visdata(bool* usedLeaves, BSPLEAF32* oldLeaves,
 	int decompressedVisSize = oldLeafCount * oldVisRowSize;
 	unsigned char* decompressedVis = new unsigned char[decompressedVisSize];
 	memset(decompressedVis, 0xFF, decompressedVisSize);
-	decompress_vis_lump(oldLeaves, lumps[LUMP_VISIBILITY], decompressedVis,
+	decompress_vis_lump(this,oldLeaves, lumps[LUMP_VISIBILITY], decompressedVis,
 		oldWorldLeaves, oldVisLeafCount - 1, oldVisLeafCount - 1, oldLeavesMemSize, bsp_header.lump[LUMP_VISIBILITY].nLength);
 
 	if (oldVisRowSize != newVisRowSize)
@@ -4302,7 +4302,7 @@ bool Bsp::validate()
 	int decompressedVisSize = leafCount * newVisRowSize;
 	unsigned char* decompressedVis = new unsigned char[decompressedVisSize];
 	memset(decompressedVis, 0xFF, decompressedVisSize);
-	decompress_vis_lump(leaves, visdata, decompressedVis,
+	decompress_vis_lump(this,leaves, visdata, decompressedVis,
 		models[0].nVisLeafs, leafCount, leafCount, decompressedVisSize, bsp_header.lump[LUMP_VISIBILITY].nLength);
 	delete decompressedVis;
 
diff --git a/src/bsp/BspMerger.cpp b/src/bsp/BspMerger.cpp
index 29f71dab..fb5004c0 100644
--- a/src/bsp/BspMerger.cpp
+++ b/src/bsp/BspMerger.cpp
@@ -1808,12 +1808,12 @@ void BspMerger::merge_vis(Bsp& mapA, Bsp& mapB)
 
 	// decompress this map's world leaves
 	// model leaves don't need to be decompressed because the game ignores VIS for them.
-	decompress_vis_lump(allLeaves, mapA.visdata, decompressedVis,
+	decompress_vis_lump(&mapA, allLeaves, mapA.visdata, decompressedVis,
 		thisWorldLeafCount, thisVisLeaves, totalVisLeaves, mapA.bsp_header.lump[LUMP_VISIBILITY].nLength, mapA.visDataLength);
 
 	// decompress other map's world-leaf vis data (skip empty first leaf, which now only the first map should have)
 	unsigned char* decompressedOtherVis = decompressedVis + thisWorldLeafCount * newVisRowSize;
-	decompress_vis_lump(allLeaves + thisWorldLeafCount, mapB.visdata, decompressedOtherVis,
+	decompress_vis_lump(&mapB,allLeaves + thisWorldLeafCount, mapB.visdata, decompressedOtherVis,
 		otherWorldLeafCount, otherLeafCount, totalVisLeaves, mapB.bsp_header.lump[LUMP_VISIBILITY].nLength, mapB.visDataLength);
 
 	// shift mapB's world leaves after mapA's world leaves
diff --git a/src/qtools/vis.cpp b/src/qtools/vis.cpp
index 2dd266db..ce83eeae 100644
--- a/src/qtools/vis.cpp
+++ b/src/qtools/vis.cpp
@@ -61,7 +61,7 @@ bool shiftVis(unsigned char* vis, int len, int offsetLeaf, int shift)
 
 	if (shift < 0)
 	{
-// TODO: memcpy for negative shifts
+		// TODO: memcpy for negative shifts
 		bitShifts += byteShifts * 8;
 		byteShifts = 0;
 	}
@@ -142,12 +142,12 @@ bool shiftVis(unsigned char* vis, int len, int offsetLeaf, int shift)
 		}
 	}
 	if (overflow)
-		print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_0993),overflow);
+		print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_0993), overflow);
 
 
 	if (byteShifts > 0)
 	{
-// TODO: detect overflows here too
+		// TODO: detect overflows here too
 		if (shift > 0)
 		{
 			unsigned char* temp = new unsigned char[MAX_MAP_LEAVES / 8];
@@ -163,7 +163,7 @@ bool shiftVis(unsigned char* vis, int len, int offsetLeaf, int shift)
 		}
 		else
 		{
-	  // TODO LOL
+			// TODO LOL
 		}
 
 	}
@@ -175,7 +175,7 @@ bool shiftVis(unsigned char* vis, int len, int offsetLeaf, int shift)
 // iterationLeaves = number of leaves to decompress vis for
 // visDataLeafCount = total leaves in this map (exluding the shared solid leaf 0)
 // newNumLeaves = total leaves that will be in the map after merging is finished (again, excluding solid leaf 0)
-void decompress_vis_lump(BSPLEAF32* leafLump, unsigned char* visLump, unsigned char* output,
+void decompress_vis_lump(Bsp* map, BSPLEAF32* leafLump, unsigned char* visLump, unsigned char* output,
 	int iterationLeaves, int visDataLeafCount, int newNumLeaves, int leafMemSize, int visLumpMemSize)
 {
 	unsigned char* dest;
@@ -196,9 +196,9 @@ void decompress_vis_lump(BSPLEAF32* leafLump, unsigned char* visLump, unsigned c
 		dest = output + i * newVisRowSize;
 		if (lastUsedIdx >= 0)
 		{
-			if ((i + 1) * sizeof(BSPLEAF32) > leafMemSize)
+			if ((i + 1) * sizeof(BSPLEAF32) >= leafMemSize)
 			{
-				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_0994),i + 1,leafMemSize / sizeof(BSPLEAF32));
+				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_0994), i + 1, leafMemSize / sizeof(BSPLEAF32));
 				return;
 			}
 
@@ -209,9 +209,9 @@ void decompress_vis_lump(BSPLEAF32* leafLump, unsigned char* visLump, unsigned c
 				continue;
 			}
 
-			if (leafLump[i + 1].nVisOffset > visLumpMemSize)
+			if (leafLump[i + 1].nVisOffset >= visLumpMemSize)
 			{
-				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_0995),leafLump[i + 1].nVisOffset,visLumpMemSize);
+				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_0995), leafLump[i + 1].nVisOffset, visLumpMemSize);
 				return;
 			}
 			// Tracing ... 
@@ -261,12 +261,12 @@ void DecompressVis(unsigned char* src, unsigned char* dest, unsigned int dest_le
 		{
 			if (out > startdst + dest_length)
 			{
-				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_0998),(int)(out - startdst),dest_length);
+				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_0998), (int)(out - startdst), dest_length);
 				return;
 			}
 			if (src > startsrc + src_length)
 			{
-				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_0999),(int)(src - startsrc),src_length);
+				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_0999), (int)(src - startsrc), src_length);
 				return;
 			}
 			*out = *src;
@@ -281,7 +281,7 @@ void DecompressVis(unsigned char* src, unsigned char* dest, unsigned int dest_le
 		{
 			if (out > startdst + dest_length)
 			{
-				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1142),(int)(out - startdst),dest_length);
+				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1142), (int)(out - startdst), dest_length);
 				return;
 			}
 			*out = 0;
@@ -308,7 +308,7 @@ int CompressVis(unsigned char* src, unsigned int src_length, unsigned char* dest
 
 		if (current_length > dest_length)
 		{
-			print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1000),current_length,dest_length);
+			print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1000), current_length, dest_length);
 			return (int)(dest_p - dest);
 		}
 
@@ -337,7 +337,7 @@ int CompressVis(unsigned char* src, unsigned int src_length, unsigned char* dest
 		current_length++;
 		if (current_length > dest_length)
 		{
-			print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1143),current_length,dest_length);
+			print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1143), current_length, dest_length);
 			return (int)(dest_p - dest);
 		}
 		*dest_p = rep;
@@ -386,7 +386,7 @@ int CompressAll(BSPLEAF32* leafs, unsigned char* uncompressed, unsigned char* ou
 	{
 		if (i + 1 >= maxLeafs)
 		{
-			print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1001),i + 1,maxLeafs);
+			print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1001), i + 1, maxLeafs);
 			delete[] sharedRows;
 			delete[] compressed;
 			return (int)(vismap_p - output);
@@ -396,7 +396,7 @@ int CompressAll(BSPLEAF32* leafs, unsigned char* uncompressed, unsigned char* ou
 		{
 			if (sharedRows[i] + 1 >= maxLeafs)
 			{
-				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1002),(int)(sharedRows[i] + 1),maxLeafs);
+				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1002), (int)(sharedRows[i] + 1), maxLeafs);
 				delete[] sharedRows;
 				delete[] compressed;
 				return (int)(vismap_p - output);
@@ -417,7 +417,7 @@ int CompressAll(BSPLEAF32* leafs, unsigned char* uncompressed, unsigned char* ou
 
 		if (vismap_p >= output + bufferSize)
 		{
-			print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1003),(void*)vismap_p,(void*)(output + bufferSize));
+			print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1003), (void*)vismap_p, (void*)(output + bufferSize));
 
 			delete[] sharedRows;
 			return (int)(vismap_p - output);
@@ -461,7 +461,7 @@ void DecompressLeafVis(unsigned char* src, unsigned int src_len, unsigned char*
 		{
 			if (out > dest + dest_length)
 			{
-				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1004),(int)(out - dest),dest_length);
+				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1004), (int)(out - dest), dest_length);
 				return;
 			}
 
@@ -478,13 +478,13 @@ void DecompressLeafVis(unsigned char* src, unsigned int src_len, unsigned char*
 		{
 			if (out > dest + dest_length)
 			{
-				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1005),(int)(out - dest),dest_length);
+				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1005), (int)(out - dest), dest_length);
 				return;
 			}
 
 			if (src > src_start + src_len)
 			{
-				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1006),(int)(out - dest),dest_length);
+				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1006), (int)(out - dest), dest_length);
 				return;
 			}
 
@@ -498,7 +498,7 @@ void DecompressLeafVis(unsigned char* src, unsigned int src_len, unsigned char*
 
 		if (src > src_start + src_len)
 		{
-			print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1144),(int)(out - dest),dest_length);
+			print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1144), (int)(out - dest), dest_length);
 			return;
 		}
 
@@ -506,7 +506,7 @@ void DecompressLeafVis(unsigned char* src, unsigned int src_len, unsigned char*
 		{
 			if (out > dest + dest_length)
 			{
-				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1007),(int)(out - dest),dest_length);
+				print_log(PRINT_RED | PRINT_INTENSITY, get_localized_string(LANG_1007), (int)(out - dest), dest_length);
 				return;
 			}
 
diff --git a/src/qtools/vis.h b/src/qtools/vis.h
index de0dec89..641b697c 100644
--- a/src/qtools/vis.h
+++ b/src/qtools/vis.h
@@ -8,7 +8,7 @@ bool shiftVis(unsigned char* vis, int len, int offsetLeaf, int shift);
 // iterationLeaves = number of leaves to decompress vis for
 // visDataLeafCount = total leaves in the map (exluding the shared solid leaf 0)
 // newNumLeaves = total leaves that will be in the map after merging is finished (again, excluding solid leaf 0)
-void decompress_vis_lump(BSPLEAF32* leafLump,  unsigned char* visLump, unsigned char* output,
+void decompress_vis_lump(Bsp * map,BSPLEAF32* leafLump,  unsigned char* visLump, unsigned char* output,
 						 int iterationLeaves, int visDataLeafCount, int newNumLeaves, int leafMemSize, int visLumpMemSize);
 
 void DecompressVis(unsigned char* src, unsigned char* dest, unsigned int dest_length, unsigned int numLeaves, unsigned int src_length);