Fix bad interaction between bootstrap autoloader and Zend Debugger/APC.

Signed-off-by: Edward Z. Yang <ezyang@mit.edu>

NEWS

@@ -29,7 +29,9 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
   are using standalone or the specialized includes files, you're
   expected to know what you're doing.
 - Stop repeatedly writing the cache file after I'm done customizing a
-  raw definition.
+  raw definition.  Reported by ajh.
+- Switch to using require_once in the Bootstrap to work around bad
+  interaction with Zend Debugger and APC.  Reported by Antonio Parraga.
 
 4.2.0, released 2010-09-15
 ! Added %Core.RemoveProcessingInstructions, which lets you remove

library/HTMLPurifier/Bootstrap.php

@@ -37,7 +37,12 @@ class HTMLPurifier_Bootstrap
     public static function autoload($class) {
         $file = HTMLPurifier_Bootstrap::getPath($class);
         if (!$file) return false;
-        require HTMLPURIFIER_PREFIX . '/' . $file;
+        // Technically speaking, it should be ok and more efficient to
+        // just do 'require', but Antonio Parraga reports that with
+        // Zend extensions such as Zend debugger and APC, this invariant
+        // may be broken.  Since we have efficient alternatives, pay
+        // the cost here and avoid the bug.
+        require_once HTMLPURIFIER_PREFIX . '/' . $file;
         return true;
     }