From 5762c41f1ad06fe6dc6a063dc5b59e04ae1d7aea Mon Sep 17 00:00:00 2001
From: cola98765 <tpodole@gmail.com>
Date: Mon, 1 Nov 2021 10:18:49 +0100
Subject: [PATCH] protect full regions against being overwritten by a partial
 one

---
 .../lod/handlers/LodDimensionFileHandler.java | 16 ++++++++++---
 .../lod/objects/VerticalLevelContainer.java   | 23 ++++++++++++-------
 2 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/src/main/java/com/seibel/lod/handlers/LodDimensionFileHandler.java b/src/main/java/com/seibel/lod/handlers/LodDimensionFileHandler.java
index 33a172570..cc516d922 100644
--- a/src/main/java/com/seibel/lod/handlers/LodDimensionFileHandler.java
+++ b/src/main/java/com/seibel/lod/handlers/LodDimensionFileHandler.java
@@ -289,6 +289,7 @@ public class LodDimensionFileHandler
 			}
 			File oldFile = new File(fileName);
 			//ClientProxy.LOGGER.info("saving region [" + region.regionPosX + ", " + region.regionPosZ + "] to file.");
+			byte[] temp = region.getLevel(detailLevel).toDataString();
 			
 			try
 			{
@@ -308,9 +309,12 @@ public class LodDimensionFileHandler
 					// (to make sure we don't overwrite a newer
 					// version file if it exists)
 					int fileVersion = LOD_SAVE_FILE_VERSION;
+					int isFull = 0;
 					try (XZCompressorInputStream inputStream = new XZCompressorInputStream(new FileInputStream(oldFile)))
 					{
 						fileVersion = inputStream.read();
+						inputStream.skip(1);
+						isFull = inputStream.read() & 0b10000000;
 						inputStream.close();
 					}
 					catch (IOException ex)
@@ -326,11 +330,17 @@ public class LodDimensionFileHandler
 						// delete anything the user may want.
 						return;
 					}
-					
+					if ((temp[1] & 0b10000000) != 0b10000000 && isFull == 0b10000000)
+					{
+						// existing file is complete while new one is only partially generate
+						// this can happen is for some reason loading failed
+						// this doesn't fix the bug, but at least protects old data
+						ClientProxy.LOGGER.error("LOD file write error. Attempted to overwrite complete region with incomplete one [" + fileName + "]");
+						return;
+					}
 					// if we got this far then we are good
 					// to overwrite the old file
 				}
-				
 				// the old file is good, now create a new temporary save file
 				File newFile = new File(fileName + TMP_FILE_EXTENSION);
 				try (XZCompressorOutputStream outputStream = new XZCompressorOutputStream(new FileOutputStream(newFile), 3))
@@ -339,7 +349,7 @@ public class LodDimensionFileHandler
 					outputStream.write(LOD_SAVE_FILE_VERSION);
 					
 					// add each LodChunk to the file
-					outputStream.write(region.getLevel(detailLevel).toDataString());
+					outputStream.write(temp);
 					outputStream.close();
 					
 					// overwrite the old file with the new one
diff --git a/src/main/java/com/seibel/lod/objects/VerticalLevelContainer.java b/src/main/java/com/seibel/lod/objects/VerticalLevelContainer.java
index f692baa1d..01cb97756 100644
--- a/src/main/java/com/seibel/lod/objects/VerticalLevelContainer.java
+++ b/src/main/java/com/seibel/lod/objects/VerticalLevelContainer.java
@@ -129,7 +129,7 @@ public class VerticalLevelContainer implements LevelContainer
 		long newData;
 		detailLevel = inputData[index];
 		index++;
-		maxVerticalData = inputData[index];
+		maxVerticalData = inputData[index] & 0b01111111;
 		index++;
 		size = 1 << (LodUtil.REGION_DETAIL_LEVEL - detailLevel);
 		int x = size * size * maxVerticalData;
@@ -181,24 +181,31 @@ public class VerticalLevelContainer implements LevelContainer
 	public byte[] toDataString()
 	{
 		int index = 0;
-		int x = size * size * maxVerticalData;
+		int x = size * size;
 		int tempIndex;
 		long current;
-		
+		boolean allGenerated = true;
 		byte[] tempData = ThreadMapUtil.getSaveContainer(detailLevel);
 		
 		tempData[index] = detailLevel;
 		index++;
 		tempData[index] = (byte) maxVerticalData;
 		index++;
-		
+		int j;
 		for (int i = 0; i < x; i++)
 		{
-			current = dataContainer[i];
-			for (tempIndex = 0; tempIndex < 8; tempIndex++)
-				tempData[index + tempIndex] = (byte) (current >>> (8 * tempIndex));
-			index += 8;
+			for (j = 0; j < maxVerticalData; j++)
+			{
+				current = dataContainer[i * maxVerticalData + j];
+				for (tempIndex = 0; tempIndex < 8; tempIndex++)
+					tempData[index + tempIndex] = (byte) (current >>> (8 * tempIndex));
+				index += 8;
+			}
+			if(!DataPointUtil.doesItExist(dataContainer[i]))
+				allGenerated = false;
 		}
+		if (allGenerated)
+			tempData[1] |= 0b10000000;
 		return tempData;
 	}