1 files changed, 36 insertions, 1 deletions

diff --git a/src/Items/ItemRedstoneDust.h b/src/Items/ItemRedstoneDust.h
index a2289239c..6d5fb521f 100644
--- a/src/Items/ItemRedstoneDust.h
+++ b/src/Items/ItemRedstoneDust.h
@@ -27,7 +27,20 @@ public:
 		BLOCKTYPE & a_BlockType, NIBBLETYPE & a_BlockMeta
 	) override
 	{
-		if (!cBlockInfo::FullyOccupiesVoxel(a_World->GetBlock(a_BlockX, a_BlockY - 1, a_BlockZ)))  // Some solid blocks, such as cocoa beans, are not suitable for dust
+		// Check if coords are out of range:
+		if ((a_BlockY <= 0) || (a_BlockY >= cChunkDef::Height))
+		{
+			return false;
+		}
+
+		// Check the block below, if it supports dust on top of it:
+		BLOCKTYPE BlockType;
+		NIBBLETYPE BlockMeta;
+		if (!a_World->GetBlockTypeMeta(a_BlockX, a_BlockY - 1, a_BlockZ, BlockType, BlockMeta))
+		{
+			return false;
+		}
+		if (!IsBlockTypeUnderSuitable(BlockType, BlockMeta))
 		{
 			return false;
 		}
@@ -36,6 +49,28 @@ public:
 		a_BlockMeta = 0;
 		return true;
 	}
+
+
+	/** Returns true if the specified block type / meta is suitable to have redstone dust on top of it. */
+	static bool IsBlockTypeUnderSuitable(BLOCKTYPE a_BlockType, NIBBLETYPE a_BlockMeta)
+	{
+		if (cBlockInfo::FullyOccupiesVoxel(a_BlockType))
+		{
+			return true;
+		}
+
+		switch (a_BlockType)
+		{
+			case E_BLOCK_NEW_STONE_SLAB:
+			case E_BLOCK_WOODEN_SLAB:
+			case E_BLOCK_STONE_SLAB:
+			{
+				// Slabs can support redstone if they're upside down:
+				return ((a_BlockMeta & 0x08) != 0);
+			}
+		}
+		return false;
+	}
 } ;