From 047615dbbe40e0d82e202f8a9483471aa54c62cd Mon Sep 17 00:00:00 2001
From: MathiewMay <mathiewmaysenhoelder@hotmail.com>
Date: Wed, 11 Mar 2026 08:34:20 -0400
Subject: [PATCH] Fix entity ID TLS key recreating on every call of
 getSmallid() for linux, this caused a ID pool corruption.

---
 Minecraft.World/Entities/Entity.cpp | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/Minecraft.World/Entities/Entity.cpp b/Minecraft.World/Entities/Entity.cpp
index 9c88a00e2..0a62c9b3e 100644
--- a/Minecraft.World/Entities/Entity.cpp
+++ b/Minecraft.World/Entities/Entity.cpp
@@ -24,7 +24,11 @@
 
 
 int Entity::entityCounter = 2048;		// 4J - changed initialiser to 2048, as we are using range 0 - 2047 as special unique smaller ids for things that need network tracked
+#ifdef _WIN32
 DWORD Entity::tlsIdx = TlsAlloc();
+#else
+pthread_key_t Entity::tlsIdx = 0;
+#endif
 
 // 4J - added getSmallId & freeSmallId methods
 unsigned int Entity::entityIdUsedFlags[2048/32] = {0};
@@ -47,7 +51,6 @@ int Entity::getSmallId()
 #ifdef _WIN32
 	if( ((size_t)TlsGetValue(tlsIdx) != 0 ) )
 #else
-	pthread_key_create(&tlsIdx, nullptr);
 	if ( ((size_t)pthread_getspecific(tlsIdx) != 0) )
 #endif
 	{
@@ -151,7 +154,16 @@ void Entity::freeSmallId(int index)
 
 void Entity::useSmallIds()
 {
-	pthread_setspecific(tlsIdx,(LPVOID)1);
+#ifdef _WIN32
+	TlsSetValue(tlsIdx, (LPVOID)1);
+#else
+	static bool keyCreated = false;
+	if (!keyCreated) {
+		pthread_key_create(&tlsIdx, nullptr);
+		keyCreated = true;
+	}
+	pthread_setspecific(tlsIdx,(void*)1);
+#endif
 }
 
 // Things also added here to be able to manage the concept of a number of extra "wandering" entities - normally path finding entities aren't allowed to