From c93d1f53beb291f8fc70f11cfe50a6d841d7675b Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sat, 11 Aug 2018 00:55:42 -0400
Subject: [PATCH] Detect and repair corrupt Region Files - Closes #1317

If the file has partial data written but not the full 8192 bytes,
then the server will be unable to load that region file...

I don't know why mojang only checks for 4096, when anything less than 8192 is a crash.

But to be safe, it will attempt to back up the file.
---
 ...tect-and-repair-corrupt-Region-Files.patch | 41 +++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 Spigot-Server-Patches/0334-Detect-and-repair-corrupt-Region-Files.patch

diff --git a/Spigot-Server-Patches/0334-Detect-and-repair-corrupt-Region-Files.patch b/Spigot-Server-Patches/0334-Detect-and-repair-corrupt-Region-Files.patch
new file mode 100644
index 000000000..1c3310255
--- /dev/null
+++ b/Spigot-Server-Patches/0334-Detect-and-repair-corrupt-Region-Files.patch
@@ -0,0 +1,41 @@
+From 791918c4893844b0cb19a6cc9a4a717bd83a1509 Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Sat, 11 Aug 2018 00:49:20 -0400
+Subject: [PATCH] Detect and repair corrupt Region Files
+
+If the file has partial data written but not the full 8192 bytes,
+then the server will be unable to load that region file...
+
+I don't know why mojang only checks for 4096, when anything less than 8192 is a crash.
+
+But to be safe, it will attempt to back up the file.
+
+diff --git a/src/main/java/net/minecraft/server/RegionFile.java b/src/main/java/net/minecraft/server/RegionFile.java
+index cba23731..07039223 100644
+--- a/src/main/java/net/minecraft/server/RegionFile.java
++++ b/src/main/java/net/minecraft/server/RegionFile.java
+@@ -41,7 +41,20 @@ public class RegionFile {
+             }
+ 
+             this.c = new RandomAccessFile(file, "rw");
+-            if (this.c.length() < 4096L) {
++            // Paper start - detect and fix incomplete headers
++            long length = this.c.length();
++            if (length < 8192 && length > 0) {
++                File corrupt = new File(file.getParentFile(), file.getName() + ".bak");
++                org.apache.logging.log4j.Logger logger = org.apache.logging.log4j.LogManager.getLogger();
++                logger.error("Region file " + file + " was incomplete. Backing up to " + corrupt + " and repairing");
++                try {
++                    java.nio.file.Files.copy(file.toPath(), corrupt.toPath());
++                } catch (IOException e) {
++                    logger.error("Error backing up corrupt file", e);
++                }
++            }
++            if (length < 8192L) {
++                // Paper end
+                 this.c.write(RegionFile.a);
+                 this.c.write(RegionFile.a);
+                 this.g += 8192;
+-- 
+2.18.0
+