From 8bf1609cccba24e2516ecb98dbf694b91fe697bf Mon Sep 17 00:00:00 2001
From: Zughy <63455151+Zughy@users.noreply.github.com>
Date: Fri, 12 Aug 2022 11:17:37 +0200
Subject: [PATCH] Fix crash when crafting callbacks return strings (#12685)

Co-authored-by: Zughy <4279489-marco_a@users.noreply.gitlab.com>
---
 builtin/game/register.lua | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/builtin/game/register.lua b/builtin/game/register.lua
index ee4edabbf..8b6f5b990 100644
--- a/builtin/game/register.lua
+++ b/builtin/game/register.lua
@@ -303,14 +303,16 @@ end
 
 function core.on_craft(itemstack, player, old_craft_list, craft_inv)
 	for _, func in ipairs(core.registered_on_crafts) do
-		itemstack = func(itemstack, player, old_craft_list, craft_inv) or itemstack
+		-- cast to ItemStack since func() could return a string
+		itemstack = ItemStack(func(itemstack, player, old_craft_list, craft_inv) or itemstack)
 	end
 	return itemstack
 end
 
 function core.craft_predict(itemstack, player, old_craft_list, craft_inv)
 	for _, func in ipairs(core.registered_craft_predicts) do
-		itemstack = func(itemstack, player, old_craft_list, craft_inv) or itemstack
+		-- cast to ItemStack since func() could return a string
+		itemstack = ItemStack(func(itemstack, player, old_craft_list, craft_inv) or itemstack)
 	end
 	return itemstack
 end