From 3069f805e286f27b11cd6e5d335545d42b125ea1 Mon Sep 17 00:00:00 2001
From: glx22 <glx@openttd.org>
Date: Fri, 24 Dec 2021 01:30:53 +0100
Subject: [PATCH] Fix #9766: Don't write uninitialised data in config file

(cherry picked from commit 50304f7164d5c88a42dcc1d09648c3ec8b2faab5)

Fixes: #344
---
 src/settings.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/settings.cpp b/src/settings.cpp
index 97adbf7723..564a5b4eb3 100644
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -386,6 +386,10 @@ void OneOfManySettingDesc::FormatValue(char *buf, const char *last, const void *
 void ManyOfManySettingDesc::FormatValue(char *buf, const char *last, const void *object) const
 {
 	uint bitmask = (uint)this->Read(object);
+	if (bitmask == 0) {
+		buf[0] = '\0';
+		return;
+	}
 	bool first = true;
 	for (uint id : SetBitIterator(bitmask)) {
 		if (!first) buf = strecpy(buf, "|", last);