diff --git a/content/base/test/Makefile.in b/content/base/test/Makefile.in
index cf92f44cb590..ae03a922f12a 100644
--- a/content/base/test/Makefile.in
+++ b/content/base/test/Makefile.in
@@ -186,6 +186,9 @@ _TEST_FILES = 	test_bug5141.html \
 		test_text_wholeText.html \
 		wholeTexty-helper.xml \
 		test_bug444030.xhtml \
+		test_NodeIterator_basics_filters.xhtml \
+		test_NodeIterator_mutations_1.xhtml \
+		test_NodeIterator_mutations_2.html \
 		$(NULL)
 
 libs:: $(_TEST_FILES)
diff --git a/content/base/test/test_NodeIterator_basics_filters.xhtml b/content/base/test/test_NodeIterator_basics_filters.xhtml
new file mode 100644
index 000000000000..9dc2905c84a0
--- /dev/null
+++ b/content/base/test/test_NodeIterator_basics_filters.xhtml
@@ -0,0 +1,117 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+<!-- NodeIterator basics and filters tests.
+     Originally written by Ian Hickson, Mochi-ified by Zack Weinberg.
+     This file based on 001.xml, 002.xml, and 010.xml from
+       http://hixie.ch/tests/adhoc/dom/traversal/node-iterator/
+     with some additional cases.
+  -->
+<head>
+  <title>DOM Traversal: NodeIterator: Basics and Filters</title>
+  <script type="text/javascript" src="/MochiKit/packed.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+<p id="display"></p>
+<div id="content" style="display: none">
+<!-- comment -->
+<?body processing instruction?>
+</div>
+<pre id="test">
+<script class="testbody" type="text/javascript"><![CDATA[
+  function compare_arrays(e, f, label) {
+    var length = (e.length > f.length) ? e.length : f.length;
+    for (var i = 0; i < length; i += 1) {
+      if (e[i] > 0) 
+        is(f[i], e[i], label + " - index " + i + ": ");
+      else
+        todo_is(f[i], -e[i], label + " - index " + i + ": ");
+    }
+  }
+
+  /** DOM Traversal: NodeIterator: Basics **/
+  // NOTE: If you change the document structure, you have to make sure
+  // the magic numbers in this array (and 'expected_f', below) match.
+  var expected = new Array(9, // document
+                           1, // html
+                           3, 8, // leading comment
+                           3, 1, // head
+                           3, 1, 3, // title
+                           3, 1, // first script tag
+                           3, 1, // second script tag
+                           3, 1, // stylesheet tag
+                           3,    // close head
+                           3, 1, // body
+                           3, 1, // p#display
+                           3, 1, // div#content
+                           3, 8, // comment
+                           3, 7, // processing instruction
+                           3,    // close div
+                           3, 1, // pre#test
+                           3, 1, 4, // script and CDATA block
+                           -3, -3, -3); // close close close
+                                        // these aren't there
+                                        // not sure why
+  var found = new Array();
+
+  var iterator = document.createNodeIterator(document,
+                                             NodeFilter.SHOW_ALL,
+                                             null, false);
+  var node;
+
+  // forwards
+  while (node = iterator.nextNode())
+    found.push(node.nodeType);
+  compare_arrays(expected, found, 'basics forward');
+
+  // backwards
+  found.length = 0;
+  while (node = iterator.previousNode())
+    found.unshift(node.nodeType);
+  compare_arrays(expected, found, 'basics backward');
+
+  /** DOM Traversal: NodeIterator: Filters **/
+  function filter(n) {
+    if (n.nodeType == 3) {
+      return NodeFilter.FILTER_SKIP;
+    } else if (n.nodeName == 'body') {
+      return NodeFilter.FILTER_REJECT; // same as _SKIP
+    }
+    return 1; // FILTER_ACCEPT
+  }
+
+  // Same warning applies to this array as to 'expected'.
+  var expect_f = new Array(9, // document
+                           1, // html
+                           8, // leading comment
+                           1, // head
+                           1, // title
+                           1, // first script tag
+                           1, // second script tag
+                           1, // stylesheet tag
+                           // body skipped
+                           1, // p#display
+                           1, // div#content
+                           8, // comment
+                           // processing instruction skipped
+                           1, // pre#test
+                           1, 4); // script and CDATA block
+
+  found.length = 0;
+  iterator = document.createNodeIterator(document, NodeFilter.SHOW_ALL,
+                                         filter, false);
+
+  // forwards
+  while (node = iterator.nextNode())
+    found.push(node.nodeType);
+  compare_arrays(expect_f, found, 'filtered forward');
+
+  // backwards
+  found.length = 0;
+  while (node = iterator.previousNode())
+    found.unshift(node.nodeType);
+  compare_arrays(expect_f, found, 'filtered backward');
+]]></script>
+</pre>
+</body>
+</html>
diff --git a/content/base/test/test_NodeIterator_mutations_1.xhtml b/content/base/test/test_NodeIterator_mutations_1.xhtml
new file mode 100644
index 000000000000..a14c1bee4b98
--- /dev/null
+++ b/content/base/test/test_NodeIterator_mutations_1.xhtml
@@ -0,0 +1,205 @@
+<html xmlns="http://www.w3.org/1999/xhtml">
+<!-- NodeIterator mutation tests.
+     Originally written by Ian Hickson, Mochi-ified by Zack Weinberg.
+     This file based on 00[3-9].xml from
+       http://hixie.ch/tests/adhoc/dom/traversal/node-iterator/
+  -->
+<head>
+  <title>DOM Traversal: NodeIterator: Mutations (1/x)</title>
+  <script type="text/javascript" src="/MochiKit/packed.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+<p id="display"></p>
+<div id="content" style="display: none">
+<span id="X"></span><span id="Y"><span id="root1"><span id="A"><span id="B"><span id="C"><span id="D"><span id="E"></span></span></span></span></span></span></span>
+<span id="root2"><span id="F"><span id="FF"></span></span><span id="G"></span><span id="H"><span id="HH"></span></span></span>
+<span id="root3"><span id="I"><span id="II"></span></span><span id="J"></span><span id="K"><span id="KK"></span></span></span>
+<span id="root4"><span id="L"></span><span id="M"><span id="MM"></span></span><span id="N"></span></span>
+<span id="root5"><span id="O"></span><span id="P"><span id="PP"></span></span><span id="Q"></span></span>
+<span id="root6"><span id="R"></span><span id="S"><span id="SS"></span></span><span id="T"></span></span>
+<span id="root7"><span id="U"></span><span id="V"><span id="VV"></span></span><span id="W"></span></span>
+</div>
+<pre id="test">
+<script class="testbody" type="text/javascript"><![CDATA[
+  /** Originally written by Ian Hickson. **/
+
+  function check(f, e, label) {
+    var eid = e.id;
+    var fid = f ? f.id : 'null';
+    is(f, e, label + ': expected ' + eid + ' have ' + fid);
+  }
+
+  var childid = 0;
+  function addChildTo(a) {
+    var x = document.createElementNS('http://www.w3.org/1999/xhtml', 'span');
+    x.id = 'X' + childid;
+    childid++;
+    ok(a, 'parent ' + (a?a.id:'undefined') + ' for child ' + x.id);
+    if (a)
+      a.appendChild(x);
+    return x;
+  }
+  function remove(a) {
+    var p = a.parentNode;
+    ok(a && p,
+       'removing ' + ( a?(a.id?a.id:'(no id)'):'undefined' )
+       + ' with parent ' + ( p?(p.id?p.id:'(no id)'):'undefined' ));
+    if (a && p)
+      p.removeChild(a);
+  }
+
+  /** Removal of nodes that should have no effect **/
+  (function () {
+    var root = $('root1');
+    var A = $('A');
+    var B = $('B');
+    var C = $('C');
+    var D = $('D');
+    var E = $('E');
+
+    var iterator = document.createNodeIterator(root, NodeFilter.SHOW_ALL,
+					       null, false);
+    check(iterator.nextNode(), root, '1.0');
+
+    // 1. Remove a node unrelated to the reference node
+    remove($('X'));
+    check(iterator.nextNode(), A, '1.1');
+
+    // 2. Remove an ancestor of the root node
+    remove($('Y'));
+    check(iterator.nextNode(), B, '1.2');
+
+    // 3. Remove the root node itself
+    remove(root);
+    check(iterator.nextNode(), C, '1.3');
+
+    // 4. Remove a descendant of the reference node
+    remove(E);
+    check(iterator.nextNode(), D, '1.4');
+  })();
+
+  /** Removal of the reference node **/
+  (function () {
+    var root = $('root2');
+    var F = $('F');
+    var FF = $('FF');
+    var G = $('G');
+    var H = $('H');
+    var iterator = document.createNodeIterator(root, NodeFilter.SHOW_ALL,
+					       null, false);
+
+    check(iterator.nextNode(), root, '2.0');
+    check(iterator.nextNode(), F,    '2.1');
+    check(iterator.nextNode(), FF,   '2.2');
+    check(iterator.nextNode(), G,    '2.3');
+    remove(G);
+    check(iterator.previousNode(), FF, '2.4');
+    remove(FF);
+    check(iterator.nextNode(), H, '2.5');
+  })();
+
+  /** Removal of the reference node (deep check) **/
+  (function () {
+    var root = $('root3');
+    var I = $('I');
+    var II = $('II');
+    var J = $('J');
+    var K = $('K');
+    var KK = $('KK');
+
+    var iterator = document.createNodeIterator(root, NodeFilter.SHOW_ALL,
+					       null, false);
+    check(iterator.nextNode(), root, '3.0');
+    check(iterator.nextNode(), I, '3.1');
+    check(iterator.nextNode(), II, '3.2');
+    check(iterator.nextNode(), J, '3.3');
+    remove(J);
+    var X = addChildTo(II);
+    check(iterator.nextNode(), X, '3.4');
+    check(iterator.previousNode(), X, '3.5');
+    remove(X);
+    var Y = addChildTo(II);
+    check(iterator.previousNode(), Y, '3.6');
+    check(iterator.nextNode(), Y, '3.7');
+    check(iterator.nextNode(), K, '3.8');
+    check(iterator.nextNode(), KK, '3.9');
+  })();
+
+  /** Removal of an ancestor of the Reference Node (forwards) **/
+  (function () {
+    var root = $('root4');
+    var L = $('L');
+    var M = $('M');
+    var MM = $('MM');
+    var N = $('N');
+
+    var iterator = document.createNodeIterator(root, NodeFilter.SHOW_ALL,
+					       null, false);
+    check(iterator.nextNode(), root, '4.1');
+    check(iterator.nextNode(), L, '4.2');
+    check(iterator.nextNode(), M, '4.3');
+    check(iterator.nextNode(), MM, '4.4');
+    remove(M);
+    check(iterator.previousNode(), L, '4.5');
+  })();
+
+  /** Removal of an ancestor of the Reference Node (forwards) (deep check) **/
+  (function () {
+    var root = $('root5');
+    var O = $('O');
+    var P = $('P');
+    var PP = $('PP');
+    var Q = $('Q');
+
+    var iterator = document.createNodeIterator(root, NodeFilter.SHOW_ALL,
+					       null, false);
+    check(iterator.nextNode(), root, '5.1');
+    check(iterator.nextNode(), O, '5.2');
+    check(iterator.nextNode(), P, '5.3');
+    check(iterator.nextNode(), PP, '5.4');
+    remove(P);
+    var X = addChildTo(O);
+    check(iterator.nextNode(), X, '5.5');
+  })();
+
+  /** Removal of an ancestor of the Reference Node (backwards) **/
+  (function () {
+    var root = $('root6');
+    var R = $('R');
+    var S = $('S');
+    var SS = $('SS');
+    var T = $('T');
+
+    var iterator = document.createNodeIterator(root, NodeFilter.SHOW_ALL,
+					       null, false);
+    check(iterator.nextNode(), root, '6.1');
+    check(iterator.nextNode(), R, '6.2');
+    check(iterator.nextNode(), S, '6.3');
+    check(iterator.nextNode(), SS, '6.4');
+    check(iterator.previousNode(), SS, '6.5');
+    remove(S);
+    check(iterator.nextNode(), T, '6.6');
+  })();
+
+  /** Removal of an ancestor of the Reference Node (backwards) (deep check) **/
+  (function () {
+    var root = $('root7');
+    var U = $('U');
+    var V = $('V');
+    var VV = $('VV');
+    var W = $('W');
+
+    var iterator = document.createNodeIterator(root, NodeFilter.SHOW_ALL,
+					       null, false);
+    check(iterator.nextNode(), root, '7.1');
+    check(iterator.nextNode(), U, '7.2');
+    check(iterator.nextNode(), V, '7.3');
+    check(iterator.nextNode(), VV, '7.4');
+    check(iterator.previousNode(), VV, '7.5');
+    remove(V);
+    var X = addChildTo(U);
+    check(iterator.previousNode(), X, '7.6');
+  })();
+]]></script></pre></body></html>
diff --git a/content/base/test/test_NodeIterator_mutations_2.html b/content/base/test/test_NodeIterator_mutations_2.html
new file mode 100644
index 000000000000..f6ebea9675b9
--- /dev/null
+++ b/content/base/test/test_NodeIterator_mutations_2.html
@@ -0,0 +1,113 @@
+<!DOCTYPE HTML>
+<html>
+<!-- NodeIterator mutation tests, 2.
+     Originally part of WebKit, Mochi-ified by Zack Weinberg.
+     This file based on node-iterator-00[...].html from
+       http://svn.webkit.org/repository/webkit/trunk/LayoutTests/traversal/
+  -->
+<head>
+ <title>DOM Traversal: NodeIterator: Mutations (2/x)</title>
+  <script type="text/javascript" src="/MochiKit/packed.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css">
+</head>
+<p id="display"></p>
+<div id="content" style="display: none">
+</div>
+<pre id="test">
+<script class="testbody" type="text/javascript">
+  function resetContent() {
+    var content = $('content');
+    content.innerHTML = ('<span id="A"><\/span><span id="B"><\/span>'
+			 + '<span id="C"><\/span><span id="D"><\/span>'
+			 + '<span id="E"><\/span><span id="F"><\/span>'
+			 + '<span id="G"><\/span><span id="H"><\/span>'
+			 + '<span id="I"><\/span>');
+    return content;
+  }
+
+  function makeSpan(id) {
+    var e = document.createElement('span');
+    e.id = id;
+    return e;
+  }
+
+  function testNodeFilter(n) {
+    if (n.tagName == 'SPAN')
+      return NodeFilter.FILTER_ACCEPT;
+    return NodeFilter.FILTER_SKIP;
+  }
+
+  function checkseq(it, root, expect) {
+    var checkIt = document.createNodeIterator(root, NodeFilter.SHOW_ELEMENT,
+					      testNodeFilter, false);
+    var printedPointer = (it.referenceNode == undefined);
+    var string = '';
+    var node;
+    while ((node = checkIt.nextNode()) != null) {
+      if (!printedPointer && it.referenceNode == node) {
+        printedPointer = true;
+	var s = '[' + node.id + '] ';
+          if (it.pointerBeforeReferenceNode)
+            string += "* " + s;
+          else
+            string += s + "* ";
+      } else {
+        string += node.id + " ";
+      }
+    }
+    is(string.slice(0, -1), expect, "sequence check");
+  }
+
+  // first a basic sanity check [node-iterator-001]
+  (function(){
+     var root = resetContent();
+     var it = document.createNodeIterator(root, NodeFilter.SHOW_ELEMENT,
+					  testNodeFilter, false);
+
+     checkseq(it, root, 'A B C D E F G H I');
+     it.nextNode();
+     checkseq(it, root, '[A] * B C D E F G H I');
+     it.previousNode();
+     checkseq(it, root, '* [A] B C D E F G H I');
+     it.previousNode();
+     checkseq(it, root, '* [A] B C D E F G H I');
+  })();
+
+  // Mutations that should not move the iterator [node-iterator-002]
+  (function(){
+     var root = resetContent();
+     var it = document.createNodeIterator(root, NodeFilter.SHOW_ELEMENT,
+					  testNodeFilter, false);
+
+     for (var i = 0; i < 4; i++)
+       it.nextNode();
+     checkseq(it, root, 'A B C [D] * E F G H I');
+
+     root.removeChild($('E'));
+     checkseq(it, root, 'A B C [D] * F G H I');
+
+     var X = makeSpan('X');
+     root.insertBefore(X, $('F'));
+     checkseq(it, root, 'A B C [D] * X F G H I');
+
+     var I = $('I');
+     root.removeChild(I);
+     root.insertBefore(I, X);
+     checkseq(it, root, 'A B C [D] * I X F G H');
+  })();
+
+  // 002 complete
+
+  /* Template
+  (function(){
+     var root = resetContent();
+     var it = document.createNodeIterator(root, NodeFilter.SHOW_ELEMENT,
+					  testNodeFilter, false);
+
+  })();
+  */
+</script>
+</pre>
+</body>
+</html>
