From e6a950c30a3fed3d72213836cddb65dac0491ac0 Mon Sep 17 00:00:00 2001
From: tour <yl_tour@posteo.de>
Date: Sun, 17 Mar 2024 14:01:05 +0100
Subject: [PATCH] crash in case of invalid api usage

---
 api.lua      | 8 ++++++++
 internal.lua | 5 +++++
 2 files changed, 13 insertions(+)

diff --git a/api.lua b/api.lua
index 1ad2bde..8d6313f 100644
--- a/api.lua
+++ b/api.lua
@@ -5,8 +5,16 @@ areas.registered_on_adds = {}
 areas.registered_on_removes = {}
 areas.registered_on_moves = {}
 
+areas.callback_origins = {}
+
 function areas:registerProtectionCondition(func)
 	table.insert(areas.registered_protection_conditions, func)
+	local debug_info = debug.getinfo(func, "S")
+	areas.callback_origins[func] = {
+		mod = core.get_current_modname() or "??",
+		source = debug_info.short_src or "??",
+		line = debug_info.linedefined or "??"
+	}
 end
 
 function areas:registerOnAdd(func)
diff --git a/internal.lua b/internal.lua
index c4e8db8..a9e16fa 100644
--- a/internal.lua
+++ b/internal.lua
@@ -222,6 +222,11 @@ function areas:canPlayerAddArea(pos1, pos2, name)
 			allowed = false
 			-- save the first error that occurred
 			errMsg = errMsg or msg
+		elseif res ~= nil then
+			local origin = areas.callback_origins[areas.registered_protection_conditions[i]]
+			error("\n[Mod] areas: Invalid api usage from mod '" ..
+					origin.mod .. "' in callback registerProtectionCondition() at " ..
+					origin.source .. ":" .. origin.line)
 		end
 	end