CatServer/patches/net/minecraft/world/chunk/storage/RegionFile.java.patch

--- ../src-base/minecraft/net/minecraft/world/chunk/storage/RegionFile.java
+++ ../src-work/minecraft/net/minecraft/world/chunk/storage/RegionFile.java
@@ -19,6 +19,9 @@
 
 public class RegionFile
 {
+    // Minecraft is limited to 256 sections per chunk. So 1MB. This can easily be override.
+    // So we extend this to use the REAL size when the count is maxed by seeking to that section and reading the length.
+    private static final boolean FORGE_ENABLE_EXTENDED_SAVE = Boolean.parseBoolean(System.getProperty("forge.enableExtendedSave", "true"));
     private static final byte[] EMPTY_SECTOR = new byte[4096];
     private final File fileName;
     private RandomAccessFile dataFile;
@@ -74,13 +77,25 @@
                 int k = this.dataFile.readInt();
                 this.offsets[j1] = k;
 
-                if (k != 0 && (k >> 8) + (k & 255) <= this.sectorFree.size())
+                int length = k & 255;
+                if (length == 255)
                 {
-                    for (int l = 0; l < (k & 255); ++l)
+                    if ((k >> 8) <= this.sectorFree.size()) { // We're maxed out, so we need to read the proper length from the section
+                        this.dataFile.seek((k >> 8) * 4096);
+                        length = (this.dataFile.readInt() + 4)/ 4096 + 1;
+                        this.dataFile.seek(j1 * 4 + 4); //Go back to where we were
+                    }
+                }
+                if (k != 0 && (k >> 8) + length <= this.sectorFree.size())
+                {
+                    for (int l = 0; l < length; ++l)
                     {
                         this.sectorFree.set((k >> 8) + l, Boolean.valueOf(false));
                     }
                 }
+                else if (length > 0)
+                    net.minecraftforge.fml.common.FMLLog.log.warn("Invalid chunk: ({}, {}) Offset: {} Length: {} runs off end file. {}", j1 % 32, (int)(j1 / 32), k >> 8, length, fileNameIn);
+
             }
 
             for (int k1 = 0; k1 < 1024; ++k1)
@@ -95,6 +110,12 @@
         }
     }
 
+    @Deprecated // TODO: remove (1.13)
+    public synchronized boolean chunkExists(int x, int z)
+    {
+        return isChunkSaved(x, z);
+    }
+
     @Nullable
 
     public synchronized DataInputStream getChunkDataInputStream(int x, int z)
@@ -117,6 +138,11 @@
                 {
                     int j = i >> 8;
                     int k = i & 255;
+                    if (k == 255)
+                    {
+                        this.dataFile.seek(j * 4096);
+                        k = (this.dataFile.readInt() + 4) / 4096 + 1;
+                    }
 
                     if (j + k > this.sectorFree.size())
                     {
@@ -129,10 +155,12 @@
 
                         if (l > 4096 * k)
                         {
+                            net.minecraftforge.fml.common.FMLLog.log.warn("Invalid chunk: ({}, {}) Offset: {} Invalid Size: {}>{} {}", x, z, j, l, k * 4096, fileName);
                             return null;
                         }
                         else if (l <= 0)
                         {
+                            net.minecraftforge.fml.common.FMLLog.log.warn("Invalid chunk: ({}, {}) Offset: {} Invalid Size: {} {}", x, z, j, l, fileName);
                             return null;
                         }
                         else
@@ -169,7 +197,7 @@
     @Nullable
     public DataOutputStream getChunkDataOutputStream(int x, int z)
     {
-        return this.outOfBounds(x, z) ? null : new DataOutputStream(new BufferedOutputStream(new DeflaterOutputStream(new RegionFile.ChunkBuffer(x, z))));
+        return this.outOfBounds(x, z) ? null : new DataOutputStream(new BufferedOutputStream(new DeflaterOutputStream(new ChunkBuffer(x, z))));
     }
 
     protected synchronized void write(int x, int z, byte[] data, int length)
@@ -179,11 +207,17 @@
             int i = this.getOffset(x, z);
             int j = i >> 8;
             int k = i & 255;
+            if (k == 255)
+            {
+                this.dataFile.seek(j * 4096);
+                k = (this.dataFile.readInt() + 4) / 4096 + 1;
+            }
             int l = (length + 5) / 4096 + 1;
 
             if (l >= 256)
             {
-                return;
+                if (!FORGE_ENABLE_EXTENDED_SAVE) return;
+                net.minecraftforge.fml.common.FMLLog.log.warn("Large Chunk Detected: ({}, {}) Size: {} {}", x, z, l, fileName);
             }
 
             if (j != 0 && k == l)
@@ -231,7 +265,7 @@
                 if (j1 >= l)
                 {
                     j = l1;
-                    this.setOffset(x, z, l1 << 8 | l);
+                    this.setOffset(x, z, l1 << 8 | (l > 255 ? 255 : l));
 
                     for (int j2 = 0; j2 < l; ++j2)
                     {
@@ -253,7 +287,7 @@
 
                     this.sizeDelta += 4096 * l;
                     this.write(j, data, length);
-                    this.setOffset(x, z, j << 8 | l);
+                    this.setOffset(x, z, j << 8 | (l > 255 ? 255 : l));
                 }
             }