From d1b5e77ca1f0f6f347a1caaf37ff40d98392e2d6 Mon Sep 17 00:00:00 2001
From: teknomunk <teknomunk@protonmail.com>
Date: Tue, 9 Apr 2024 23:09:10 +0000
Subject: [PATCH] Fix crashes

---
 mods/CORE/mcl_util/init.lua           | 16 ++++++++++------
 mods/ENTITIES/mcl_minecarts/carts.lua |  6 +++---
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/mods/CORE/mcl_util/init.lua b/mods/CORE/mcl_util/init.lua
index c9a012803..7b3127db6 100644
--- a/mods/CORE/mcl_util/init.lua
+++ b/mods/CORE/mcl_util/init.lua
@@ -1188,11 +1188,7 @@ end
 function mcl_util.get_luaentity_from_uuid(uuid)
 	return minetest.luaentities[ mcl_util.get_active_object_id_from_uuid(uuid) ]
 end
-function mcl_util.get_uuid(obj)
-	local le = obj:get_luaentity()
-
-	if le._uuid then return le._uuid end
-
+function mcl_util.gen_uuid()
 	-- Generate a random 128-bit ID that can be assumed to be unique
 	-- To have a 1% chance of a collision, there would have to be 1.6x10^76 IDs generated
 	-- https://en.wikipedia.org/wiki/Birthday_problem#Probability_table
@@ -1200,7 +1196,15 @@ function mcl_util.get_uuid(obj)
 	for i = 1,16 do
 		u[#u + 1] = string.format("%02X",math.random(1,255))
 	end
-	le._uuid = table.concat(u)
+	return table.concat(u)
+end
+function mcl_util.assign_uuid(obj)
+	assert(obj)
+
+	local le = obj:get_luaentity()
+	if le._uuid then return le._uuid end
+
+	le._uuid = mcl_util.gen_uuid()
 
 	-- Update the cache with this new id
 	aoid = mcl_util.get_active_object_id(obj)
diff --git a/mods/ENTITIES/mcl_minecarts/carts.lua b/mods/ENTITIES/mcl_minecarts/carts.lua
index e66504598..78cc552f7 100644
--- a/mods/ENTITIES/mcl_minecarts/carts.lua
+++ b/mods/ENTITIES/mcl_minecarts/carts.lua
@@ -107,7 +107,7 @@ function DEFAULT_CART_DEF:on_activate(staticdata, dtime_s)
 	-- Transfer older data
 	local data = minetest.deserialize(staticdata) or {}
 	if not data.uuid then
-		data.uuid  = mcl_util.get_uuid(self.object)
+		data.uuid  = mcl_util.assign_uuid(self.object)
 	end
 	self._seq = data.seq or 1
 
@@ -202,7 +202,7 @@ function DEFAULT_CART_DEF:on_step(dtime)
 	-- Regen
 	local hp = self.object:get_hp()
 	local time_now = minetest.get_gametime()
-	if hp < MINECART_MAX_HP and staticdata.last_regen <= time_now - 1 then
+	if hp < MINECART_MAX_HP and (staticdata.last_regen or 0) <= time_now - 1 then
 		staticdata.last_regen = time_now
 		hp = hp + 1
 		self.object:set_hp(hp)
@@ -308,7 +308,7 @@ function mcl_minecarts.place_minecart(itemstack, pointed_thing, placer)
 	local entity_id = entity_mapping[itemstack:get_name()]
 
 	-- Setup cart data
-	local uuid = mcl_util.get_uuid(cart)
+	local uuid = mcl_util.gen_uuid()
 	data = make_staticdata( nil, railpos, cart_dir )
 	data.uuid = uuid
 	data.cart_type = entity_id