diff --git a/library/HTMLPurifier.php b/library/HTMLPurifier.php
index cf581452..c46ccf15 100644
--- a/library/HTMLPurifier.php
+++ b/library/HTMLPurifier.php
@@ -59,7 +59,7 @@ class HTMLPurifier
         $generator = new HTMLPurifier_Generator();
         return $generator->generateFromTokens(
             $strategy->execute(
-                $lexer->tokenizeHTML($html)
+                $lexer->tokenizeHTML($html), $config
             )
         );
     }
diff --git a/library/HTMLPurifier/ChildDef.php b/library/HTMLPurifier/ChildDef.php
index b7893d81..30664cf5 100644
--- a/library/HTMLPurifier/ChildDef.php
+++ b/library/HTMLPurifier/ChildDef.php
@@ -12,6 +12,13 @@
 // we may end up writing custom code for each HTML case
 // in order to make it self correcting
 
+HTMLPurifier_ConfigDef::define(
+    'Core', 'EscapeInvalidChildren', false,
+    'When true, a child is found that is not allowed in the context of the '.
+    'parent element will be transformed into text as if it were ASCII. When '.
+    'false, that element (and all its descendants) will be silently dropped.'
+);
+
 class HTMLPurifier_ChildDef
 {
     var $type;
@@ -40,7 +47,7 @@ class HTMLPurifier_ChildDef_Custom extends HTMLPurifier_ChildDef
         $reg = preg_replace('/([#a-zA-Z0-9_.-]+)/', '(,?\\0)', $reg);
         $this->_pcre_regex = $reg;
     }
-    function validateChildren($tokens_of_children) {
+    function validateChildren($tokens_of_children, $config, $context) {
         $list_of_children = '';
         $nesting = 0; // depth into the nest
         foreach ($tokens_of_children as $token) {
@@ -85,7 +92,7 @@ class HTMLPurifier_ChildDef_Required extends HTMLPurifier_ChildDef
     }
     var $allow_empty = false;
     var $type = 'required';
-    function validateChildren($tokens_of_children) {
+    function validateChildren($tokens_of_children, $config, $context) {
         // if there are no tokens, delete parent node
         if (empty($tokens_of_children)) return false;
         
@@ -106,6 +113,9 @@ class HTMLPurifier_ChildDef_Required extends HTMLPurifier_ChildDef
         // a little sanity check to make sure it's not ALL whitespace
         $all_whitespace = true;
         
+        // some configuration
+        $escape_invalid_children = $config->get('Core', 'EscapeInvalidChildren');
+        
         foreach ($tokens_of_children as $token) {
             if (!empty($token->is_whitespace)) {
                 $result[] = $token;
@@ -125,21 +135,21 @@ class HTMLPurifier_ChildDef_Required extends HTMLPurifier_ChildDef
                 $is_deleting = false;
                 if (!isset($this->elements[$token->name])) {
                     $is_deleting = true;
-                    if ($pcdata_allowed) {
-                        //$result[] = new HTMLPurifier_Token_Text(
-                        //    $this->gen->generateFromToken($token)
-                        //);
+                    if ($pcdata_allowed && $escape_invalid_children) {
+                        $result[] = new HTMLPurifier_Token_Text(
+                            $this->gen->generateFromToken($token)
+                        );
                     }
                     continue;
                 }
             }
             if (!$is_deleting) {
                 $result[] = $token;
-            } elseif ($pcdata_allowed) {
-                //$result[] =
-                //    new HTMLPurifier_Token_Text(
-                //        $this->gen->generateFromToken( $token )
-                //    );
+            } elseif ($pcdata_allowed && $escape_invalid_children) {
+                $result[] =
+                    new HTMLPurifier_Token_Text(
+                        $this->gen->generateFromToken( $token )
+                    );
             } else {
                 // drop silently
             }
@@ -157,8 +167,8 @@ class HTMLPurifier_ChildDef_Optional extends HTMLPurifier_ChildDef_Required
 {
     var $allow_empty = true;
     var $type = 'optional';
-    function validateChildren($tokens_of_children) {
-        $result = parent::validateChildren($tokens_of_children);
+    function validateChildren($tokens_of_children, $config, $context) {
+        $result = parent::validateChildren($tokens_of_children, $config, $context);
         if ($result === false) return array();
         return $result;
     }
@@ -170,7 +180,7 @@ class HTMLPurifier_ChildDef_Empty extends HTMLPurifier_ChildDef
     var $allow_empty = true;
     var $type = 'empty';
     function HTMLPurifier_ChildDef_Empty() {}
-    function validateChildren() {
+    function validateChildren($tokens_of_children, $config, $context) {
         return false;
     }
 }
@@ -186,14 +196,16 @@ class HTMLPurifier_ChildDef_Chameleon extends HTMLPurifier_ChildDef
         $this->block  = new HTMLPurifier_ChildDef_Optional($block);
     }
     
-    function validateChildren($tokens_of_children, $context) {
+    function validateChildren($tokens_of_children, $config, $context) {
         switch ($context) {
             case 'unknown':
             case 'inline':
-                $result = $this->inline->validateChildren($tokens_of_children);
+                $result = $this->inline->validateChildren(
+                    $tokens_of_children, $config, $context);
                 break;
             case 'block':
-                $result = $this->block->validateChildren($tokens_of_children);
+                $result = $this->block->validateChildren(
+                    $tokens_of_children, $config, $context);
                 break;
             default:
                 trigger_error('Invalid context', E_USER_ERROR);
diff --git a/library/HTMLPurifier/Strategy/Composite.php b/library/HTMLPurifier/Strategy/Composite.php
index 178edae9..8faa528c 100644
--- a/library/HTMLPurifier/Strategy/Composite.php
+++ b/library/HTMLPurifier/Strategy/Composite.php
@@ -12,8 +12,7 @@ class HTMLPurifier_Strategy_Composite
         trigger_error('Attempt to instantiate abstract object', E_USER_ERROR);
     }
     
-    function execute($tokens, $config = null) {
-        if (!$config) $config = HTMLPurifier_Config::createDefault();
+    function execute($tokens, $config) {
         foreach ($this->strategies as $strategy) {
             $tokens = $strategy->execute($tokens, $config);
         }
diff --git a/library/HTMLPurifier/Strategy/FixNesting.php b/library/HTMLPurifier/Strategy/FixNesting.php
index f0845cf5..7b04c534 100644
--- a/library/HTMLPurifier/Strategy/FixNesting.php
+++ b/library/HTMLPurifier/Strategy/FixNesting.php
@@ -40,7 +40,7 @@ class HTMLPurifier_Strategy_FixNesting extends HTMLPurifier_Strategy
         $this->definition = HTMLPurifier_Definition::instance();
     }
     
-    function execute($tokens) {
+    function execute($tokens, $config) {
         
         //####################################################################//
         // Pre-processing
@@ -147,7 +147,8 @@ class HTMLPurifier_Strategy_FixNesting extends HTMLPurifier_Strategy
                 $child_def = $def->child;
                 
                 // have DTD child def validate children
-                $result = $child_def->validateChildren($child_tokens, $context);
+                $result = $child_def->validateChildren(
+                    $child_tokens, $config,$context);
                 
                 // determine whether or not this element has any exclusions
                 $excludes = $def->excludes;
diff --git a/library/HTMLPurifier/Strategy/MakeWellFormed.php b/library/HTMLPurifier/Strategy/MakeWellFormed.php
index 4192cbbf..d3f6b8bb 100644
--- a/library/HTMLPurifier/Strategy/MakeWellFormed.php
+++ b/library/HTMLPurifier/Strategy/MakeWellFormed.php
@@ -15,7 +15,7 @@ class HTMLPurifier_Strategy_MakeWellFormed extends HTMLPurifier_Strategy
         $this->definition = HTMLPurifier_Definition::instance();
     }
     
-    function execute($tokens) {
+    function execute($tokens, $config) {
         $result = array();
         $current_nesting = array();
         foreach ($tokens as $token) {
diff --git a/library/HTMLPurifier/Strategy/RemoveForeignElements.php b/library/HTMLPurifier/Strategy/RemoveForeignElements.php
index c0290593..f1d0e79f 100644
--- a/library/HTMLPurifier/Strategy/RemoveForeignElements.php
+++ b/library/HTMLPurifier/Strategy/RemoveForeignElements.php
@@ -24,7 +24,7 @@ class HTMLPurifier_Strategy_RemoveForeignElements extends HTMLPurifier_Strategy
         $this->definition = HTMLPurifier_Definition::instance();
     }
     
-    function execute($tokens) {
+    function execute($tokens, $config) {
         $result = array();
         foreach($tokens as $token) {
             if (!empty( $token->is_tag )) {
diff --git a/library/HTMLPurifier/Strategy/ValidateAttributes.php b/library/HTMLPurifier/Strategy/ValidateAttributes.php
index 6c49780f..995b28b3 100644
--- a/library/HTMLPurifier/Strategy/ValidateAttributes.php
+++ b/library/HTMLPurifier/Strategy/ValidateAttributes.php
@@ -23,10 +23,7 @@ class HTMLPurifier_Strategy_ValidateAttributes extends HTMLPurifier_Strategy
         $this->definition = HTMLPurifier_Definition::instance();
     }
     
-    function execute($tokens, $config = null) {
-        
-        // load default configuration object if none passed
-        if (!$config) $config = HTMLPurifier_Config::createDefault();
+    function execute($tokens, $config) {
         
         // setup StrategyContext
         $context = new HTMLPurifier_AttrContext();
diff --git a/tests/HTMLPurifier/ChildDefTest.php b/tests/HTMLPurifier/ChildDefTest.php
index 4e2f651a..5a15526e 100644
--- a/tests/HTMLPurifier/ChildDefTest.php
+++ b/tests/HTMLPurifier/ChildDefTest.php
@@ -7,6 +7,7 @@ require_once 'HTMLPurifier/Generator.php';
 class HTMLPurifier_ChildDefTest extends UnitTestCase
 {
     
+    var $def;
     var $lex;
     var $gen;
     
@@ -16,21 +17,24 @@ class HTMLPurifier_ChildDefTest extends UnitTestCase
         parent::UnitTestCase();
     }
     
-    function assertSeries($inputs, $expect, $def, $context = array()) {
+    function assertSeries($inputs, $expect, $config, $context = array()) {
         foreach ($inputs as $i => $input) {
             $tokens = $this->lex->tokenizeHTML($input);
             
-            if (isset($context[$i])) {
-                $result = $def->validateChildren($tokens, $context[$i]);
-            } else {
-                $result = $def->validateChildren($tokens);
+            if (!isset($context[$i])) {
+                $context[$i] = null;
+            }
+            if (!isset($config[$i])) {
+                $config[$i] = HTMLPurifier_Config::createDefault();
             }
             
+            $result = $this->def->validateChildren($tokens, $config[$i], $context[$i]);
+            
             if (is_bool($expect[$i])) {
-                $this->assertIdentical($expect[$i], $result);
+                $this->assertIdentical($expect[$i], $result, "Test $i: %s");
             } else {
                 $result_html = $this->gen->generateFromTokens($result);
-                $this->assertEqual($expect[$i], $result_html, "Test $i: %s");
+                $this->assertIdentical($expect[$i], $result_html, "Test $i: %s");
                 paintIf($result_html, $result_html != $expect[$i]);
             }
         }
@@ -39,9 +43,11 @@ class HTMLPurifier_ChildDefTest extends UnitTestCase
     function test_custom() {
         
         // the table definition
-        $def = new HTMLPurifier_ChildDef_Custom(
+        $this->def = new HTMLPurifier_ChildDef_Custom(
             '(caption?, (col*|colgroup*), thead?, tfoot?, (tbody+|tr+))');
         
+        $inputs = $expect = $config = array();
+        
         $inputs[0] = '';
         $expect[0] = false;
         
@@ -58,7 +64,7 @@ class HTMLPurifier_ChildDefTest extends UnitTestCase
         $inputs[3] = '<col></col><col></col><col></col><tr></tr>';
         $expect[3] = true;
         
-        $this->assertSeries($inputs, $expect, $def);
+        $this->assertSeries($inputs, $expect, $config);
         
     }
     
@@ -82,7 +88,8 @@ class HTMLPurifier_ChildDefTest extends UnitTestCase
     
     function test_required_pcdata_forbidden() {
         
-        $def = new HTMLPurifier_ChildDef_Required('dt | dd');
+        $this->def = new HTMLPurifier_ChildDef_Required('dt | dd');
+        $inputs = $expect = $config = array();
         
         $inputs[0] = '';
         $expect[0] = false;
@@ -105,21 +112,31 @@ class HTMLPurifier_ChildDefTest extends UnitTestCase
         $inputs[5] = "\t      ";
         $expect[5] = false;
         
-        $this->assertSeries($inputs, $expect, $def);
+        $this->assertSeries($inputs, $expect, $config);
         
     }
     
     function test_required_pcdata_allowed() {
-        $def = new HTMLPurifier_ChildDef_Required('#PCDATA | b');
+        $this->def = new HTMLPurifier_ChildDef_Required('#PCDATA | b');
+        
+        $inputs = $expect = $config = array();
         
         $inputs[0] = '<b>Bold text</b><img />';
-        $expect[0] = '<b>Bold text</b>&lt;img /&gt;';
+        $expect[0] = '<b>Bold text</b>';
         
-        $this->assertSeries($inputs, $expect, $def);
+        // with child escaping on
+        $inputs[1] = '<b>Bold text</b><img />';
+        $expect[1] = '<b>Bold text</b>&lt;img /&gt;';
+        $config[1] = HTMLPurifier_Config::createDefault();
+        $config[1]->set('Core', 'EscapeInvalidChildren', true);
+        
+        $this->assertSeries($inputs, $expect, $config);
     }
     
     function test_optional() {
-        $def = new HTMLPurifier_ChildDef_Optional('b | i');
+        $this->def = new HTMLPurifier_ChildDef_Optional('b | i');
+        
+        $inputs = $expect = $config = array();
         
         $inputs[0] = '<b>Bold text</b><img />';
         $expect[0] = '<b>Bold text</b>';
@@ -127,16 +144,19 @@ class HTMLPurifier_ChildDefTest extends UnitTestCase
         $inputs[1] = 'Not allowed text';
         $expect[1] = '';
         
-        $this->assertSeries($inputs, $expect, $def);
+        $this->assertSeries($inputs, $expect, $config);
     }
     
     function test_chameleon() {
         
-        $def = new HTMLPurifier_ChildDef_Chameleon(
+        $this->def = new HTMLPurifier_ChildDef_Chameleon(
             'b | i', // allowed only when in inline context
             'b | i | div' // allowed only when in block context
         );
         
+        $inputs = $expect = $config = array();
+        $context = array();
+        
         $inputs[0] = '<b>Allowed.</b>';
         $expect[0] = true;
         $context[0] = 'inline';
@@ -149,7 +169,7 @@ class HTMLPurifier_ChildDefTest extends UnitTestCase
         $expect[2] = true;
         $context[2] = 'block';
         
-        $this->assertSeries($inputs, $expect, $def, $context);
+        $this->assertSeries($inputs, $expect, $config, $context);
         
     }
     
diff --git a/tests/HTMLPurifier/Strategy/CoreTest.php b/tests/HTMLPurifier/Strategy/CoreTest.php
index 0cbff05e..1d1dd219 100644
--- a/tests/HTMLPurifier/Strategy/CoreTest.php
+++ b/tests/HTMLPurifier/Strategy/CoreTest.php
@@ -12,6 +12,10 @@ class HTMLPurifier_Strategy_CoreTest
         
         $inputs = array();
         $expect = array();
+        $config = array();
+        
+        $config_escape = HTMLPurifier_Config::createDefault();
+        $config_escape->set('Core', 'EscapeInvalidChildren', true);
         
         $inputs[0] = '';
         $expect[0] = '';
@@ -19,19 +23,17 @@ class HTMLPurifier_Strategy_CoreTest
         $inputs[1] = '<b>Make well formed.';
         $expect[1] = '<b>Make well formed.</b>';
         
-        // behavior may change
         $inputs[2] = '<b><div>Fix nesting.</div></b>';
-        $expect[2] = '<b>&lt;div&gt;Fix nesting.&lt;/div&gt;</b>';
+        $expect[2] = '<b></b>';
         
         // behavior may change
         $inputs[3] = '<asdf>Foreign element removal.</asdf>';
         $expect[3] = '&lt;asdf&gt;Foreign element removal.&lt;/asdf&gt;';
         
-        // behavior may change
         $inputs[4] = '<foo><b><div>All three.</div></b>';
-        $expect[4] = '&lt;foo&gt;<b>&lt;div&gt;All three.&lt;/div&gt;</b>';
+        $expect[4] = '&lt;foo&gt;<b></b>';
         
-        $this->assertStrategyWorks($strategy, $inputs, $expect);
+        $this->assertStrategyWorks($strategy, $inputs, $expect, $config);
     }
     
 }
diff --git a/tests/HTMLPurifier/Strategy/FixNestingTest.php b/tests/HTMLPurifier/Strategy/FixNestingTest.php
index ab54fbf1..b5fa0ae9 100644
--- a/tests/HTMLPurifier/Strategy/FixNestingTest.php
+++ b/tests/HTMLPurifier/Strategy/FixNestingTest.php
@@ -13,6 +13,10 @@ class HTMLPurifier_Strategy_FixNestingTest
         
         $inputs = array();
         $expect = array();
+        $config = array();
+        
+        $config_escape = HTMLPurifier_Config::createDefault();
+        $config_escape->set('Core', 'EscapeInvalidChildren', true);
         
         // next id = 4
         
@@ -27,7 +31,12 @@ class HTMLPurifier_Strategy_FixNestingTest
         
         // illegal block in inline, element -> text
         $inputs[2] = '<b><div>Illegal div.</div></b>';
-        $expect[2] = '<b>&lt;div&gt;Illegal div.&lt;/div&gt;</b>';
+        $expect[2] = '<b></b>';
+        
+        // same test with different configuration (fragile)
+        $inputs[13]  = '<b><div>Illegal div.</div></b>';
+        $expect[13] = '<b>&lt;div&gt;Illegal div.&lt;/div&gt;</b>';
+        $config[13] = $config_escape;
         
         // test of empty set that's required, resulting in removal of node
         $inputs[3] = '<ul></ul>';
@@ -63,13 +72,20 @@ class HTMLPurifier_Strategy_FixNestingTest
         
         // block in inline ins not allowed
         $inputs[11] = '<span><ins><div>Not allowed!</div></ins></span>';
-        $expect[11] = '<span><ins>&lt;div&gt;Not allowed!&lt;/div&gt;</ins></span>';
+        $expect[11] = '<span><ins></ins></span>';
+        
+        // block in inline ins not allowed
+        $inputs[14] = '<span><ins><div>Not allowed!</div></ins></span>';
+        $expect[14] = '<span><ins>&lt;div&gt;Not allowed!&lt;/div&gt;</ins></span>';
+        $config[14] = $config_escape;
         
         // test exclusions
         $inputs[12] = '<a><span><a>Not allowed</a></span></a>';
         $expect[12] = '<a><span></span></a>';
         
-        $this->assertStrategyWorks($strategy, $inputs, $expect);
+        // next test is *15*
+        
+        $this->assertStrategyWorks($strategy, $inputs, $expect, $config);
     }
     
 }
diff --git a/tests/HTMLPurifier/StrategyHarness.php b/tests/HTMLPurifier/StrategyHarness.php
index 12dd9338..27c0c71d 100644
--- a/tests/HTMLPurifier/StrategyHarness.php
+++ b/tests/HTMLPurifier/StrategyHarness.php
@@ -28,11 +28,10 @@ class HTMLPurifier_StrategyHarness extends UnitTestCase
     function assertStrategyWorks($strategy, $inputs, $expect, $config = array()) {
         foreach ($inputs as $i => $input) {
             $tokens = $this->lex->tokenizeHTML($input);
-            if (isset($config[$i])) {
-                $result_tokens = $strategy->execute($tokens, $config[$i]);
-            } else {
-                $result_tokens = $strategy->execute($tokens);
+            if (!isset($config[$i])) {
+                $config[$i] = HTMLPurifier_Config::createDefault();
             }
+            $result_tokens = $strategy->execute($tokens, $config[$i]);
             $result = $this->gen->generateFromTokens($result_tokens);
             $this->assertEqual($expect[$i], $result, "Test $i: %s");
             paintIf($result, $result != $expect[$i]);