2 files changed, 8 insertions, 2 deletions

diff --git a/src/BlockArea.cpp b/src/BlockArea.cpp
index 938351207..eb25d624d 100644
--- a/src/BlockArea.cpp
+++ b/src/BlockArea.cpp
@@ -336,6 +336,12 @@ void cBlockArea::Create(int a_SizeX, int a_SizeY, int a_SizeZ, int a_DataTypes)
 		);
 		return;
 	}
+
+	// Warn if the height is too much, but proceed with the creation:
+	if (a_SizeY > cChunkDef::Height)
+	{
+		LOGWARNING("Creating a cBlockArea with height larger than world height (%d). Continuing, but the area may misbehave.", a_SizeY);
+	}
 	
 	Clear();
 	int BlockCount = a_SizeX * a_SizeY * a_SizeZ;
@@ -540,7 +546,7 @@ bool cBlockArea::Write(cForEachChunkProvider * a_ForEachChunkProvider, int a_Min
 	else if (a_MinBlockY > cChunkDef::Height - m_Size.y)
 	{
 		LOGWARNING("%s: MinBlockY + m_SizeY more than chunk height, adjusting to chunk height", __FUNCTION__);
-		a_MinBlockY = cChunkDef::Height - m_Size.y;
+		a_MinBlockY = std::max(cChunkDef::Height - m_Size.y, 0);
 	}
 
 	return a_ForEachChunkProvider->WriteBlockArea(*this, a_MinBlockX, a_MinBlockY, a_MinBlockZ, a_DataTypes);
diff --git a/src/Chunk.cpp b/src/Chunk.cpp
index a3192f638..d9410dc8d 100644
--- a/src/Chunk.cpp
+++ b/src/Chunk.cpp
@@ -411,7 +411,7 @@ void cChunk::WriteBlockArea(cBlockArea & a_Area, int a_MinBlockX, int a_MinBlock
 	int OffZ = BlockStartZ - m_PosZ * cChunkDef::Width;
 	int BaseX = BlockStartX - a_MinBlockX;
 	int BaseZ = BlockStartZ - a_MinBlockZ;
-	int SizeY = a_Area.GetSizeY();
+	int SizeY = std::min(a_Area.GetSizeY(), cChunkDef::Height - a_MinBlockY);
 
 	// TODO: Improve this by not calling FastSetBlock() and doing the processing here
 	// so that the heightmap is touched only once for each column.