Fix segfault in deprecation logging due to tail call, log by default (#10174)

2 files changed, 32 insertions, 8 deletions

diff --git a/src/script/common/c_internal.cpp b/src/script/common/c_internal.cpp
index 6df1f8b7b..ad5f836c5 100644
--- a/src/script/common/c_internal.cpp
+++ b/src/script/common/c_internal.cpp
@@ -155,24 +155,28 @@ static void script_log(lua_State *L, const std::string &message,
 		infostream << script_get_backtrace(L) << std::endl;
 }
 
-void log_deprecated(lua_State *L, const std::string &message, int stack_depth)
+DeprecatedHandlingMode get_deprecated_handling_mode()
 {
 	static thread_local bool configured = false;
-	static thread_local bool do_log = false;
-	static thread_local bool do_error = false;
+	static thread_local DeprecatedHandlingMode ret = DeprecatedHandlingMode::Ignore;
 
 	// Only read settings on first call
 	if (!configured) {
 		std::string value = g_settings->get("deprecated_lua_api_handling");
 		if (value == "log") {
-			do_log = true;
+			ret = DeprecatedHandlingMode::Log;
 		} else if (value == "error") {
-			do_log = true;
-			do_error = true;
+			ret = DeprecatedHandlingMode::Error;
 		}
 		configured = true;
 	}
 
-	if (do_log)
-		script_log(L, message, warningstream, do_error, stack_depth);
+	return ret;
+}
+
+void log_deprecated(lua_State *L, const std::string &message, int stack_depth)
+{
+	DeprecatedHandlingMode mode = get_deprecated_handling_mode();
+	if (mode != DeprecatedHandlingMode::Ignore)
+		script_log(L, message, warningstream, mode == DeprecatedHandlingMode::Error, stack_depth);
 }
diff --git a/src/script/common/c_internal.h b/src/script/common/c_internal.h
index 442546332..452c2dd5e 100644
--- a/src/script/common/c_internal.h
+++ b/src/script/common/c_internal.h
@@ -114,5 +114,25 @@ void script_error(lua_State *L, int pcall_result, const char *mod, const char *f
 void script_run_callbacks_f(lua_State *L, int nargs,
 	RunCallbacksMode mode, const char *fxn);
 
+enum class DeprecatedHandlingMode {
+	Ignore,
+	Log,
+	Error
+};
+
+/**
+ * Reads `deprecated_lua_api_handling` in settings, returns cached value.
+ *
+ * @return DeprecatedHandlingMode
+ */
+DeprecatedHandlingMode get_deprecated_handling_mode();
+
+/**
+ * Handles a deprecation warning based on user settings
+ *
+ * @param L Lua State
+ * @param message The deprecation method
+ * @param stack_depth How far on the stack to the first user function (ie: not builtin or core)
+ */
 void log_deprecated(lua_State *L, const std::string &message,
 	int stack_depth=1);