From 637dfbf90aa681358e7b6fe1f0cba6e74e055ff3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marcel=20Fabian=20Kr=C3=BCger?= <tex@2krueger.de>
Date: Tue, 19 Dec 2023 23:27:31 +0100
Subject: [PATCH] Escaping control characters

---
 luamml-xmlwriter.lua | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/luamml-xmlwriter.lua b/luamml-xmlwriter.lua
index cbdc1f1..47d4385 100644
--- a/luamml-xmlwriter.lua
+++ b/luamml-xmlwriter.lua
@@ -10,8 +10,11 @@ local escapes = {
   ['&'] = "&amp;",
 }
 local function escape_text(text)
-  return string.gsub(tostring(text), '["<>&]', escapes)
+  return string.gsub(string.gsub(tostring(text), '["<>&]', escapes), '[\x00-\x08\x0B\x0C\x0E-\x20]', function(x)
+    return string.format('^^%02x', string.byte(x))
+  end)
 end
+print("<node>", escape_text"<node>")
 
 local attrs = {}
 local function write_elem(tree, indent)