CGI::Util#escapeHTML

# File tmp/rubies/ruby-3.0.5/lib/cgi/util.rb, line 41
def escapeHTML(string)
  enc = string.encoding
  unless enc.ascii_compatible?
    if enc.dummy?
      origenc = enc
      enc = Encoding::Converter.asciicompat_encoding(enc)
      string = enc ? string.encode(enc) : string.b
    end
    table = Hash[TABLE_FOR_ESCAPE_HTML__.map {|pair|pair.map {|s|s.encode(enc)}}]
    string = string.gsub(/#{"['&\"<>]".encode(enc)}/, table)
    string.encode!(origenc) if origenc
    return string
  end
  string.gsub(/['&\"<>]/, TABLE_FOR_ESCAPE_HTML__)
end