Add sanity check against ze1_compatibility_mode.

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

INSTALL

@@ -18,6 +18,7 @@ with these contents.
 HTML Purifier is PHP 5 only, and is actively tested from PHP 5.0.5 and
 up. It has no core dependencies with other libraries. PHP
 4 support was deprecated on December 31, 2007 with HTML Purifier 3.0.0.
+HTML Purifier is not compatible with zend.ze1_compatibility_mode.
 
 These optional extensions can enhance the capabilities of HTML Purifier:
 

NEWS

@@ -18,6 +18,10 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
 - Fix removal of id attributes under certain conditions by ensuring
   armor attributes are preserved when recreating tags.
 - Check if schema.ser was corrupted.
+- Check if zend.ze1_compatibility_mode is on, and error out if it is.
+  This safety check is only done for HTMLPurifier.auto.php; if you
+  are using standalone or the specialized includes files, you're
+  expected to know what you're doing.
 
 4.2.0, released 2010-09-15
 ! Added %Core.RemoveProcessingInstructions, which lets you remove

library/HTMLPurifier.autoload.php

@@ -3,6 +3,7 @@
 /**
  * @file
  * Convenience file that registers autoload handler for HTML Purifier.
+ * It also does some sanity checks.
  */
 
 if (function_exists('spl_autoload_register') && function_exists('spl_autoload_unregister')) {
@@ -18,4 +19,8 @@ if (function_exists('spl_autoload_register') && function_exists('spl_autoload_un
     }
 }
 
+if (ini_get('zend.ze1_compatibility_mode')) {
+    trigger_error("HTML Purifier is not compatible with zend.ze1_compatibility_mode; please turn it off", E_USER_ERROR);
+}
+
 // vim: et sw=4 sts=4

tests/HTMLPurifier/PHPT/ze1_compatibility_mode.phpt

@@ -0,0 +1,14 @@
+--TEST--
+Error with zend.ze1_compatibility_mode test
+--PRESKIPIF--
+<?php
+if (version_compare(PHP_VERSION, '5.3.0') >= 0) {
+    echo 'skip - ze1_compatibility_mode not present in PHP 5.3 or later';
+}
+--INI--
+zend.ze1_compatibility_mode = 1
+--FILE--
+<?php
+require '../library/HTMLPurifier.auto.php';
+--EXPECTF--
+Fatal error: HTML Purifier is not compatible with zend.ze1_compatibility_mode; please turn it off in %s

tests/PHPT/Section/PRESKIPIF.php

@@ -0,0 +1,36 @@
+<?php
+
+class PHPT_Section_PRESKIPIF implements PHPT_Section_RunnableBefore
+{
+    private $_data = null;
+    private $_runner_factory = null;
+    
+    public function __construct($data)
+    {
+        $this->_data = $data;
+        $this->_runner_factory = new PHPT_CodeRunner_Factory();
+    }
+    
+    public function run(PHPT_Case $case)
+    {
+        // @todo refactor this code into PHPT_Util class as its used in multiple places
+        $filename = dirname($case->filename) . '/' . basename($case->filename, '.php') . '.skip.php';
+        
+        // @todo refactor to PHPT_CodeRunner
+        file_put_contents($filename, $this->_data);
+        $runner = $this->_runner_factory->factory($case);
+        $runner->ini = "";
+        $response = $runner->run($filename)->output;
+        unlink($filename);
+        
+        if (preg_match('/^skip( - (.*))?/', $response, $matches)) {
+            $message = !empty($matches[2]) ? $matches[2] : '';
+            throw new PHPT_Case_VetoException($message);
+        }
+    }
+    
+    public function getPriority()
+    {
+        return -2;
+    }
+}