Simon Willison’s Weblog

Minor bug fix in IXR

11th July 2003

I’ve fixed a small but vital bug in the Incutio XML-RPC library. The library was causing errors when certain unicode characters were used in strings. This is because I was using PHP’s htmlentities() function to encode strings before transmission. This escapes all of the characters that need escaping (<, >, &, " and ’) but also escapes a number of other characters that have an HTML entity equivalent. The problem is that these additional entities are defined in HTML but not in XML, so XML parsers were choking on them when they tried to parse the resulting message. I’ve fixed the bug now by switching to using htmlspecialchars() instead. Thanks to the several people who reported this one (it took me a while to figure out) and to Marc Logemann who’s blog entry finally helped me crack it.