add utf8.escape_xml and alias - string.escape_xml

res/modules/internal/extensions/string.lua

@@ -105,6 +105,7 @@ end
 string.lower = utf8.lower
 string.upper = utf8.upper
 string.escape = utf8.escape
+string.escape_xml = utf8.escape_xml
 
 local meta = getmetatable("")
 

src/logic/scripting/lua/libs/libutf8.cpp

@@ -88,6 +88,11 @@ static int l_escape(lua::State* L) {
     return lua::pushstring(L, util::escape(string));
 }
 
+static int l_escape_xml(lua::State* L) {
+    auto string = lua::require_lstring(L, 1);
+    return lua::pushstring(L, util::escape_xml(string));
+}
+
 const luaL_Reg utf8lib[] = {
     {"tobytes", lua::wrap<l_tobytes>},
     {"tostring", lua::wrap<l_tostring>},
@@ -98,5 +103,6 @@ const luaL_Reg utf8lib[] = {
     {"lower", lua::wrap<l_lower>},
     {"encode", lua::wrap<l_encode>},
     {"escape", lua::wrap<l_escape>},
+    {"escape_xml", lua::wrap<l_escape_xml>},
     {nullptr, nullptr}
 };

src/util/stringutil.cpp

@@ -60,6 +60,33 @@ std::string util::escape(std::string_view s, bool escapeUnicode) {
     return ss.str();
 }
 
+std::string util::escape_xml(std::string_view s) {
+    std::stringstream ss;
+    for (char c : s) {
+        switch (c) {
+            case '&':
+                ss << "&amp;";
+                break;
+            case '<':
+                ss << "&lt;";
+                break;
+            case '>':
+                ss << "&gt;";
+                break;
+            case '"':
+                ss << "&quot;";
+                break;
+            case '\'':
+                ss << "&apos;";
+                break;
+            default:
+                ss << c;
+                break;
+        }
+    }
+    return ss.str();
+}
+
 std::string util::quote(const std::string& s) {
     return escape(s, false);
 }

src/util/stringutil.hpp

@@ -10,6 +10,9 @@ namespace util {
     /// @brief Function used for string serialization in text formats
     std::string escape(std::string_view s, bool escapeUnicode=true);
 
+    /// @brief Escape all special XML characters 
+    std::string escape_xml(std::string_view s);
+
     /// @brief Function used for error messages
     std::string quote(const std::string& s);