From 7deccaf19c1c8fb20dfa13daadae5943e4100f3d Mon Sep 17 00:00:00 2001
From: daoge_cmd <3523206925@qq.com>
Date: Thu, 4 Apr 2024 19:23:40 +0800
Subject: [PATCH] fix: fix a possible NPE in chunk service

---
 .../allaymc/server/world/service/AllayChunkService.java  | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/Allay-Server/src/main/java/org/allaymc/server/world/service/AllayChunkService.java b/Allay-Server/src/main/java/org/allaymc/server/world/service/AllayChunkService.java
index af56f8d8a..aa2acd742 100644
--- a/Allay-Server/src/main/java/org/allaymc/server/world/service/AllayChunkService.java
+++ b/Allay-Server/src/main/java/org/allaymc/server/world/service/AllayChunkService.java
@@ -176,15 +176,16 @@ public CompletableFuture<Chunk> loadChunk(int x, int z) {
         if (isChunkLoaded(hashXZ)) {
             throw new IllegalStateException("Chunk is already loaded");
         }
+        CompletableFuture<Chunk> future;
         // Prevent multiple threads from putting the same chunk into loadingChunks at the same time and wasting computing resources
-        var presentValue = loadingChunks.putIfAbsent(hashXZ, worldStorage.readChunk(x, z, DimensionInfo.OVERWORLD)
+        var presentValue = loadingChunks.putIfAbsent(hashXZ, future = worldStorage.readChunk(x, z, DimensionInfo.OVERWORLD)
                 .exceptionally(t -> {
-                    log.error("Error while reading chunk (" + x + "," + z + ") !", t);
+                    log.error("Error while reading chunk ({},{}) !", x, z, t);
                     return AllayUnsafeChunk.builder().emptyChunk(x, z, dimension.getDimensionInfo()).toSafeChunk();
                 })
                 .thenApplyAsync(this::generateChunkIfNeed, Server.getInstance().getComputeThreadPool())
                 .exceptionally(t -> {
-                    log.error("Error while generating chunk (" + x + "," + z + ") !", t);
+                    log.error("Error while generating chunk ({},{}) !", x, z, t);
                     return AllayUnsafeChunk.builder().emptyChunk(x, z, dimension.getDimensionInfo()).toSafeChunk();
                 })
                 .thenApply(prepareChunk -> {
@@ -196,7 +197,7 @@ public CompletableFuture<Chunk> loadChunk(int x, int z) {
                 })
         );
         if (presentValue == null) {
-            return loadingChunks.get(hashXZ);
+            return future;
         } else {
             return presentValue;
         }