From 1330ad5cdb7076dab36f8efe8efd5c686a0c4933 Mon Sep 17 00:00:00 2001
From: Joey Arhar <jarhar@chromium.org>
Date: Mon, 15 Jul 2024 12:59:07 -0700
Subject: [PATCH 01/13] Relax <select> parser

This patch makes the parser allow additional tags in <select> besides
<option>, <optgroup>, and <hr>, mostly by removing the "in select" and
"in select in table" parser modes.

In order to replicate the behavior where opening a <select> tag within
another open <select> tag inserts a </select> close tag, a traversal
through the stack of open elements was added which I borrowed from the
<button> part of the parser.

This will need test changes to be implemented in html5lib.

Fixes https://github.com/whatwg/html/issues/10310
---
 source | 464 +++++++++++++++++----------------------------------------
 1 file changed, 138 insertions(+), 326 deletions(-)

diff --git a/source b/source
index de407dd6dc0..22183d6927d 100644
--- a/source
+++ b/source
@@ -3208,12 +3208,14 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
      <li>The <dfn data-x-href="https://dom.spec.whatwg.org/#concept-tree-child" data-x="concept-tree-child">child</dfn> concept</li>
      <li>The <dfn data-x-href="https://dom.spec.whatwg.org/#concept-tree-root">root</dfn> and <dfn data-x-href="https://dom.spec.whatwg.org/#concept-shadow-including-root">shadow-including root</dfn> concepts</li>
      <li>The <dfn data-x-href="https://dom.spec.whatwg.org/#concept-tree-inclusive-ancestor">inclusive ancestor</dfn>,
+             <dfn data-x-href="https://dom.spec.whatwg.org/#concept-tree-ancestor">ancestor</dfn>,
              <dfn data-x-href="https://dom.spec.whatwg.org/#concept-tree-descendant">descendant</dfn>,
              <dfn data-x="concept-shadow-including-ancestor" data-x-href="https://dom.spec.whatwg.org/#concept-shadow-including-ancestor">shadow-including ancestor</dfn>,
              <dfn data-x-href="https://dom.spec.whatwg.org/#concept-shadow-including-descendant">shadow-including descendant</dfn>,
              <dfn data-x-href="https://dom.spec.whatwg.org/#concept-shadow-including-inclusive-descendant">shadow-including inclusive descendant</dfn>, and
              <dfn data-x-href="https://dom.spec.whatwg.org/#concept-shadow-including-inclusive-ancestor">shadow-including inclusive ancestor</dfn> concepts</li>
      <li>The <dfn data-x-href="https://dom.spec.whatwg.org/#concept-tree-first-child">first child</dfn>,
+             <dfn data-x-href="https://dom.spec.whatwg.org/#concept-tree-last-child">last child</dfn>,
              <dfn data-x-href="https://dom.spec.whatwg.org/#concept-tree-next-sibling">next sibling</dfn>,
              <dfn data-x-href="https://dom.spec.whatwg.org/#concept-tree-previous-sibling">previous sibling</dfn>, and
              <dfn data-x-href="https://dom.spec.whatwg.org/#concept-tree-parent">parent</dfn> concepts</li>
@@ -53299,10 +53301,25 @@ interface <dfn interface>HTMLSelectElement</dfn> : <span>HTMLElement</span> {
 
   </div>
 
-  <p>The <dfn data-x="concept-select-option-list">list of options</dfn> for a <code>select</code>
-  element consists of all the <code>option</code> element children of the <code>select</code>
-  element, and all the <code>option</code> element children of all the <code>optgroup</code> element
-  children of the <code>select</code> element, in <span>tree order</span>.</p>
+  <p>To get the <dfn data-x="concept-select-option-list">list of options</dfn> given a
+  <code>select</code> element <var>select</var>:</p>
+
+  <ol>
+   <li><p>Let <var>options</var> be « ».</p></li>
+
+   <li>
+    <p><span data-x="list iterate">For each</span> <var>node</var> of <var>select</var>'s
+    <span data-x="descendant">descendants</span> in <span>tree order</span> except the descendants
+    which are <code>select</code> elements and their subtrees:</p>
+
+    <ol>
+     <li><p>If <var>node</var> is an <code>option</code> element, then <span
+     data-x="list append">append</span> <var>node</var> to <var>options</var>.</p></li>
+    </ol>
+   </li>
+
+   <li><p>Return <var>options</var>.</p></li>
+  </ol>
 
   <p>The <dfn element-attr for="select"><code data-x="attr-select-required">required</code></dfn>
   attribute is a <span>boolean attribute</span>. When specified, the user will be required to select
@@ -53401,34 +53418,6 @@ interface <dfn interface>HTMLSelectElement</dfn> : <span>HTMLElement</span> {
    to false.</p></li>
   </ol>
 
-  <p>The <code>option</code> <span data-x="html element insertion steps">HTML element insertion
-  steps</span>, given <var>insertedNode</var>, are:</p>
-
-  <ol>
-   <li><p>If <var>insertedNode</var>'s parent is a <code>select</code> element, or
-   <var>insertedNode</var>'s parent is an <code>optgroup</code> element whose parent is a
-   <code>select</code> element, then run that <code>select</code> element's <span>selectedness
-   setting algorithm</span>.</p></li>
-  </ol>
-
-  <p>The <code>option</code> <span data-x="html element removing steps">HTML element removing
-  steps</span>, given <var>removedNode</var> and <var>oldParent</var>, are:</p>
-
-  <ol>
-   <li><p>If <var>oldParent</var> is a <code>select</code> element, or <var>oldParent</var> is an
-   <code>optgroup</code> element whose parent is a <code>select</code> element, then run that
-   <code>select</code> element's <span>selectedness setting algorithm</span>.</p></li>
-  </ol>
-
-  <p>The <code>optgroup</code> <span data-x="html element removing steps">HTML element removing
-  steps</span>, given <var>removedNode</var> and <var>oldParent</var>, are:</p>
-
-  <ol>
-   <li><p>If <var>oldParent</var> is a <code>select</code> element and <var>removedNode</var> has an
-   <var>option</var> child, then run <var>oldParent</var>'s <span>selectedness setting
-   algorithm</span>.</p></li>
-  </ol>
-
   <p>If an <code>option</code> element in the <span data-x="concept-select-option-list">list of
   options</span> <dfn data-x="ask for a reset">asks for a reset</dfn>, then run that
   <code>select</code> element's <span>selectedness setting algorithm</span>.</p>
@@ -54156,6 +54145,35 @@ interface <dfn interface>HTMLOptionElement</dfn> : <span>HTMLElement</span> {
 
   </div>
 
+  <p>The <code>option</code> <span>HTML element insertion steps</span>, given
+  <var>insertedOption</var>, are:</p>
+
+  <ol>
+   <li>
+    <p>For each <var>ancestor</var> of <var>option</var>'s <span
+    data-x="ancestor">ancestors</span>:</p>
+
+    <ol>
+     <li><p>If <var>ancestor</var> is a <code>select</code> element, then run the <span>selectedness
+     setting algorithm</span> given <var>select</var> and return.</p></li>
+    </ol>
+   </li>
+  </ol>
+
+  <p>The <code>option</code> <span>HTML element removing steps</span>, given
+  <var>removedOption</var> and <var>oldParent</var>, are:</p>
+
+  <ol>
+   <li>
+    <p>For each <var>ancestor</var> of <var>oldParent</var>'s <span data-x="inclusive
+    ancestor">inclusive ancestors</span>:</p>
+
+    <ol>
+     <li><p>If <var>ancestor</var> is a <code>select</code> element, then run the <span>selectedness
+     setting algorithm</span> given <var>select</var> and return.</p></li>
+    </ol>
+  </ol>
+
   <dl class="domintro">
    <dt><code data-x=""><var>option</var>.<span subdfn data-x="dom-option-selected">selected</span></code></dt>
 
@@ -124353,25 +124371,22 @@ dictionary <dfn dictionary>StorageEventInit</dfn> : <span>EventInit</span> {
   caption">in caption</span>", "<span data-x="insertion mode: in column group">in column
   group</span>", "<span data-x="insertion mode: in table body">in table body</span>", "<span
   data-x="insertion mode: in row">in row</span>", "<span data-x="insertion mode: in cell">in
-  cell</span>", "<span data-x="insertion mode: in select">in select</span>", "<span data-x="insertion
-  mode: in select in table">in select in table</span>", "<span data-x="insertion mode: in
-  template">in template</span>", "<span data-x="insertion mode: after body">after body</span>",
-  "<span data-x="insertion mode: in frameset">in frameset</span>", "<span data-x="insertion mode:
-  after frameset">after frameset</span>", "<span data-x="insertion mode: after after body">after
-  after body</span>", and "<span data-x="insertion mode: after after frameset">after after
-  frameset</span>" during the course of the parsing, as described in the <span>tree
-  construction</span> stage. The insertion mode affects how tokens are processed and whether CDATA
-  sections are supported.</p>
+  cell</span>", "<span data-x="insertion mode: in template">in template</span>", "<span
+  data-x="insertion mode: after body">after body</span>", "<span data-x="insertion mode: in
+  frameset">in frameset</span>", "<span data-x="insertion mode: after frameset">after
+  frameset</span>", "<span data-x="insertion mode: after after body">after after body</span>", and
+  "<span data-x="insertion mode: after after frameset">after after frameset</span>" during the
+  course of the parsing, as described in the <span>tree construction</span> stage. The insertion
+  mode affects how tokens are processed and whether CDATA sections are supported.</p>
 
   <p>Several of these modes, namely "<span data-x="insertion mode: in head">in head</span>", "<span
-  data-x="insertion mode: in body">in body</span>", "<span data-x="insertion mode: in table">in
-  table</span>", and "<span data-x="insertion mode: in select">in select</span>", are special, in
-  that the other modes defer to them at various times. When the algorithm below says that the user
-  agent is to do something "<dfn>using the rules for</dfn> the <var>m</var> insertion
-  mode", where <var>m</var> is one of these modes, the user agent must use the rules
-  described under the <var>m</var> <span>insertion mode</span>'s section, but must leave
-  the <span>insertion mode</span> unchanged unless the rules in <var>m</var> themselves
-  switch the <span>insertion mode</span> to a new value.</p>
+  data-x="insertion mode: in body">in body</span>", and "<span data-x="insertion mode: in table">in
+  table</span>", are special, in that the other modes defer to them at various times. When the
+  algorithm below says that the user agent is to do something "<dfn>using the rules for</dfn> the
+  <var>m</var> insertion mode", where <var>m</var> is one of these modes, the user agent must use
+  the rules described under the <var>m</var> <span>insertion mode</span>'s section, but must leave
+  the <span>insertion mode</span> unchanged unless the rules in <var>m</var> themselves switch the
+  <span>insertion mode</span> to a new value.</p>
 
   <p>When the insertion mode is switched to "<span data-x="insertion mode: text">text</span>" or
   "<span data-x="insertion mode: in table text">in table text</span>", the <dfn>original insertion
@@ -124402,37 +124417,6 @@ dictionary <dfn dictionary>StorageEventInit</dfn> : <span>EventInit</span> {
    parsing algorithm</span> (<span>fragment case</span>), set <var>node</var> to the <var
    data-x="concept-frag-parse-context">context</var> element passed to that algorithm.</p></li>
 
-   <li>
-    <p>If <var>node</var> is a <code>select</code> element, run these substeps:</p>
-
-    <ol>
-     <li><p>If <var>last</var> is true, jump to the step below labeled
-     <i>done</i>.</p></li>
-
-     <li><p>Let <var>ancestor</var> be <var>node</var>.</p></li>
-
-     <li><p><i>Loop</i>: If <var>ancestor</var> is the first node in the <span>stack of
-     open elements</span>, jump to the step below labeled <i>done</i>.</p></li>
-
-     <li><p>Let <var>ancestor</var> be the node before <var>ancestor</var> in the
-     <span>stack of open elements</span>.</p></li>
-
-     <li><p>If <var>ancestor</var> is a <code>template</code> node, jump to the step below
-     labeled <i>done</i>.</p></li>
-
-     <li><p>If <var>ancestor</var> is a <code>table</code> node, switch the <span>insertion
-     mode</span> to "<span data-x="insertion mode: in select in table">in select in table</span>"
-     and return.</p></li> <!-- consider
-     <table><tr><td><select><template></template><caption></table>
-     https://software.hixie.ch/utilities/js/live-dom-viewer/?saved=2374 -->
-
-     <li><p>Jump back to the step labeled <i>loop</i>.</p></li>
-
-     <li><p><i>Done</i>: Switch the <span>insertion mode</span> to "<span data-x="insertion mode: in
-     select">in select</span>" and return.</p></li>
-    </ol>
-   </li>
-
    <li><p>If <var>node</var> is a <code>td</code> or <code>th</code> element and <var>last</var> is
    false, then switch the <span>insertion mode</span> to "<span data-x="insertion mode: in cell">in
    cell</span>" and return.</p></li>
@@ -124631,6 +124615,7 @@ dictionary <dfn dictionary>StorageEventInit</dfn> : <span>EventInit</span> {
    <li><code>th</code></li>
    <li><code>marquee</code></li>
    <li><code>object</code></li>
+   <li><code>select</code></li>
    <li><code>template</code></li>
    <li><span>MathML <code>mi</code></span></li>
    <li><span>MathML <code>mo</code></span></li>
@@ -124677,17 +124662,6 @@ dictionary <dfn dictionary>StorageEventInit</dfn> : <span>EventInit</span> {
    <li><code>template</code> in the <span>HTML namespace</span></li>
   </ul>
 
-  <p>The <span>stack of open elements</span> is said to <dfn data-x="has an element in select
-  scope">have a particular element in select scope</dfn> when it <span data-x="has an element in the
-  specific scope">has that element in the specific scope</span> consisting of all element types
-  <em>except</em> the following:</p>
-
-  <ul class="brief">
-   <!--<li><code>select</code> in the <span>HTML namespace</span></li>-->
-   <li><code>optgroup</code> in the <span>HTML namespace</span></li>
-   <li><code>option</code> in the <span>HTML namespace</span></li>
-  </ul>
-
   <p>Nothing happens if at any time any of the elements in the <span>stack of open elements</span>
   are moved to a new location in, or removed from, the <code>Document</code> tree. In particular,
   the stack is not changed in this situation. This can cause, amongst other strange effects, content
@@ -129324,6 +129298,24 @@ document.body.appendChild(text);
     <code>p</code> element in button scope</span>, then <span>close a <code>p</code>
     element</span>.</p>
 
+    <p>If the <span>stack of open elements</span> <span data-x="has an element in scope">has a
+    <code>select</code> element in scope</span> and has either <span data-x="has an element in
+    scope">an <code>option</code> element in scope</span> or <span data-x="has an element in
+    scope">an <code>optgroup</code> element in scope</span>, then:</p>
+
+    <ol>
+     <li><p><span>Generate implied end tags</span> except for <code>option</code> and
+     <code>optgroup</code> elements.</p></li>
+
+     <li><p>If the <span>current node</span> is not now an <code>option</code> or
+     <code>optgroup</code> element, this is a <span>parse error</span>.</p></li>
+
+     <li><p>While the <span>stack of open elements</span> <span data-x="has an element in scope">has
+     an <code>option</code> element in scope</span> or <span data-x="has an element in scope">has an
+     <code>optgroup</code> element in scope</span>, pop an element from the <span>stack of open
+     elements</span>.</p></li>
+    </ol>
+
     <p><span>Insert an HTML element</span> for the token. Immediately pop the <span>current
     node</span> off the <span>stack of open elements</span>.</p>
 
@@ -129393,25 +129385,70 @@ document.body.appendChild(text);
 
    <dt>A start tag whose tag name is "select"</dt>
    <dd>
+    <p>If the <span>stack of open elements</span> <span data-x="has an element in scope">has a
+    <code>select</code> element in scope</span>, then:</p>
+
+    <ol>
+     <li><p><span>Parse error</span>.</p></li>
+
+     <li><p>Pop elements from the <span>stack of open elements</span> until a <code>select</code>
+     element has been popped from the stack.</p></li>
+    </ol>
+
     <p><span>Reconstruct the active formatting elements</span>, if any.</p>
 
     <p><span>Insert an HTML element</span> for the token.</p>
 
     <p>Set the <span>frameset-ok flag</span> to "not ok".</p>
+   </dd>
+
+   <dt>A start tag whose tag name is "option"</dt>
+   <dd>
+    <p>If the <span>stack of open elements</span> <span data-x="has an element in scope">has a
+    <code>select</code> element in scope</span> and has a <span data-x="has an element in scope">has
+    an <code>option</code> element in scope</span>, then:</p>
+
+    <ol>
+     <li><p><span>Generate implied end tags</span> except for <code>option</code> elements.</p></li>
+
+     <li><p>If the <span>current node</span> is not now an <code>option</code> element, this is a
+     <span>parse error</span>.</p></li>
+
+     <li><p>While the <span>stack of open elements</span> <span data-x="has an element in scope">has
+     an <code>option</code> element in scope</span>, pop an element from the <span>stack of open
+     elements</span>.</p></li>
+    </ol>
+
+    <p><span>Reconstruct the active formatting elements</span>, if any.</p>
 
-    <p>If the <span>insertion mode</span> is one of "<span data-x="insertion mode: in table">in
-    table</span>", "<span data-x="insertion mode: in caption">in caption</span>", "<span
-    data-x="insertion mode: in table body">in table body</span>", "<span data-x="insertion mode: in
-    row">in row</span>", or "<span data-x="insertion mode: in cell">in cell</span>", then switch the
-    <span>insertion mode</span> to "<span data-x="insertion mode: in select in table">in select in
-    table</span>". Otherwise, switch the <span>insertion mode</span> to "<span data-x="insertion
-    mode: in select">in select</span>".</p>
+    <p><span>Insert an HTML element</span> for the token.</p>
    </dd>
 
-   <dt>A start tag whose tag name is one of: "optgroup", "option"</dt>
+   <dt>A start tag whose tag name is "optgroup"</dt>
    <dd>
-    <p>If the <span>current node</span> is an <code>option</code> element, then pop the
-    <span>current node</span> off the <span>stack of open elements</span>.</p>
+    <p>If the <span>stack of open elements</span> <span data-x="has an element in scope">has a
+    <code>select</code> element in scope</span> and has either <span data-x="has an element in
+    scope">an <code>option</code> element in scope</span> or <span data-x="has an element in
+    scope">an <code>optgroup</code> element in scope</span>, then:</p>
+
+    <ol>
+     <li><p><span>Generate implied end tags</span> except for <code>option</code> and
+     <code>optgroup</code> elements.</p></li>
+
+     <li><p>If the <span>current node</span> is not now an <code>option</code> or
+     <code>optgroup</code> element, this is a <span>parse error</span>.</p></li>
+
+     <li><p><span>Generate implied end tags</span> except for <code>optgroup</code>
+     elements.</p></li>
+
+     <li><p>If the <span>current node</span> is not now an <code>optgroup</code> element, this is a
+     <span>parse error</span>.</p></li>
+
+     <li><p>While the <span>stack of open elements</span> <span data-x="has an element in scope">has
+     an <code>option</code> element in scope</span> or <span data-x="has an element in scope">has an
+     <code>optgroup</code> element in scope</span>, pop an element from the <span>stack of open
+     elements</span>.</p></li>
+    </ol>
 
     <p><span>Reconstruct the active formatting elements</span>, if any.</p>
 
@@ -130539,231 +130576,6 @@ document.body.appendChild(text);
   same time, nor can it have neither when the <span>close the cell</span> algorithm is invoked.</p>
 
 
-  <h6 id="parsing-main-inselect">The "<dfn data-x="insertion mode: in select">in select</dfn>" insertion mode</h6>
-
-  <p>When the user agent is to apply the rules for the "<span data-x="insertion mode: in select">in
-  select</span>" <span>insertion mode</span>, the user agent must handle the token as follows:</p>
-
-  <dl class="switch">
-
-   <dt>A character token that is U+0000 NULL</dt>
-   <dd>
-    <p><span>Parse error</span>. Ignore the token.</p>
-   </dd>
-
-   <dt>Any other character token</dt>
-   <dd>
-    <p><span data-x="insert a character">Insert the token's character</span>.</p>
-   </dd>
-
-   <dt>A comment token</dt>
-   <dd>
-    <p><span>Insert a comment</span>.</p>
-   </dd>
-
-   <dt>A DOCTYPE token</dt>
-   <dd>
-    <p><span>Parse error</span>. Ignore the token.</p>
-   </dd>
-
-   <dt>A start tag whose tag name is "html"</dt>
-   <dd>
-    <p>Process the token <span>using the rules for</span> the "<span data-x="insertion mode: in
-    body">in body</span>" <span>insertion mode</span>.</p>
-   </dd>
-
-   <dt>A start tag whose tag name is "option"</dt>
-   <dd>
-    <!-- fake </option> (maybe) -->
-    <p>If the <span>current node</span> is an <code>option</code> element, pop that node from the
-    <span>stack of open elements</span>.</p>
-    <!-- end of fake </option> -->
-
-    <p><span>Insert an HTML element</span> for the token.</p>
-   </dd>
-
-   <dt>A start tag whose tag name is "optgroup"</dt>
-   <dd>
-    <!-- fake </option> (maybe) -->
-    <p>If the <span>current node</span> is an <code>option</code> element, pop that node from the
-    <span>stack of open elements</span>.</p>
-    <!-- end of fake </option> -->
-
-    <!-- fake </optgroup> (maybe) -->
-    <p>If the <span>current node</span> is an <code>optgroup</code> element, pop that node from the
-    <span>stack of open elements</span>.</p>
-    <!-- end of fake </optgroup> -->
-
-    <p><span>Insert an HTML element</span> for the token.</p>
-   </dd>
-
-   <dt>A start tag whose tag name is "hr"</dt>
-   <dd>
-    <!-- fake </option> (maybe) -->
-    <p>If the <span>current node</span> is an <code>option</code> element, pop that node from the
-    <span>stack of open elements</span>.</p>
-    <!-- end of fake </option> -->
-
-    <!-- fake </optgroup> (maybe) -->
-    <p>If the <span>current node</span> is an <code>optgroup</code> element, pop that node from the
-    <span>stack of open elements</span>.</p>
-    <!-- end of fake </optgroup> -->
-
-    <p><span>Insert an HTML element</span> for the token. Immediately pop the <span>current
-    node</span> off the <span>stack of open elements</span>.</p>
-
-    <p><span data-x="acknowledge self-closing flag">Acknowledge the token's <i data-x="self-closing
-    flag">self-closing flag</i></span>, if it is set.</p>
-   </dd>
-
-   <dt>An end tag whose tag name is "optgroup"</dt>
-   <dd>
-    <!-- fake </option> (maybe) -->
-    <p>First, if the <span>current node</span> is an <code>option</code> element, and the node
-    immediately before it in the <span>stack of open elements</span> is an <code>optgroup</code>
-    element, then pop the <span>current node</span> from the <span>stack of open
-    elements</span>.</p>
-    <!-- end of fake </option> -->
-
-    <p>If the <span>current node</span> is an <code>optgroup</code> element, then pop that node from
-    the <span>stack of open elements</span>. Otherwise, this is a <span>parse error</span>; ignore
-    the token.</p>
-   </dd>
-
-   <dt>An end tag whose tag name is "option"</dt>
-   <dd>
-    <p>If the <span>current node</span> is an <code>option</code> element, then pop that node from
-    the <span>stack of open elements</span>. Otherwise, this is a <span>parse error</span>; ignore
-    the token.</p>
-   </dd>
-
-   <dt>An end tag whose tag name is "select"</dt>
-   <dd>
-    <p>If the <span>stack of open elements</span> does not <span data-x="has an element in select
-    scope">have a <code>select</code> element in select scope</span>, this is a <span>parse
-    error</span>; ignore the token. (<span>fragment case</span>)</p>
-
-    <p>Otherwise:</p>
-
-    <p>Pop elements from the <span>stack of open elements</span> until a <code>select</code> element
-    has been popped from the stack.</p>
-
-    <p><span>Reset the insertion mode appropriately</span>.</p>
-   </dd>
-
-   <dt>A start tag whose tag name is "select"</dt>
-   <dd>
-    <p><span>Parse error</span>.</p>
-
-    <!-- fake </select> -->
-    <p>If the <span>stack of open elements</span> does not <span data-x="has an element in select
-    scope">have a <code>select</code> element in select scope</span>, ignore the token.
-    (<span>fragment case</span>)</p>
-
-    <p>Otherwise:</p>
-
-    <p>Pop elements from the <span>stack of open elements</span> until a <code>select</code> element
-    has been popped from the stack.</p>
-
-    <p><span>Reset the insertion mode appropriately</span>.</p>
-    <!-- end of fake </select> -->
-
-    <p class="note">It just gets treated like an end tag.</p>
-   </dd>
-
-   <dt>A start tag whose tag name is one of: "input", "keygen", "textarea"</dt>
-   <dd>
-    <p><span>Parse error</span>.</p>
-
-    <!-- fake </select> -->
-    <p>If the <span>stack of open elements</span> does not <span data-x="has an element in select
-    scope">have a <code>select</code> element in select scope</span>, ignore the token.
-    (<span>fragment case</span>)</p>
-
-    <p>Otherwise:</p>
-
-    <p>Pop elements from the <span>stack of open elements</span> until a <code>select</code> element
-    has been popped from the stack.</p>
-
-    <p><span>Reset the insertion mode appropriately</span>.</p>
-    <!-- end of fake </select> -->
-
-    <p>Reprocess the token.</p>
-   </dd>
-
-   <dt>A start tag whose tag name is one of: "script", "template"</dt>
-   <dt>An end tag whose tag name is "template"</dt>
-   <dd>
-    <p>Process the token <span>using the rules for</span> the "<span data-x="insertion mode: in
-    head">in head</span>" <span>insertion mode</span>.</p>
-   </dd>
-
-   <dt>An end-of-file token</dt>
-   <dd>
-    <p>Process the token <span>using the rules for</span> the "<span data-x="insertion mode: in
-    body">in body</span>" <span>insertion mode</span>.</p>
-   </dd>
-
-   <dt>Anything else</dt>
-   <dd>
-    <p><span>Parse error</span>. Ignore the token.</p>
-   </dd>
-  </dl>
-
-
-  <h6 id="parsing-main-inselectintable">The "<dfn data-x="insertion mode: in select in table">in select in table</dfn>" insertion mode</h6>
-
-  <p>When the user agent is to apply the rules for the "<span data-x="insertion mode: in select in
-  table">in select in table</span>" <span>insertion mode</span>, the user agent must handle the
-  token as follows:</p>
-
-  <dl class="switch">
-
-   <dt>A start tag whose tag name is one of: "caption", "table", "tbody", "tfoot", "thead", "tr",
-   "td", "th"</dt>
-   <dd>
-    <p><span>Parse error</span>.</p>
-
-    <!-- fake </select> -->
-    <p>Pop elements from the <span>stack of open elements</span> until a <code>select</code> element
-    has been popped from the stack.</p>
-
-    <p><span>Reset the insertion mode appropriately</span>.</p>
-    <!-- end of fake </select> -->
-
-    <p>Reprocess the token.</p>
-   </dd>
-
-   <dt>An end tag whose tag name is one of: "caption", "table", "tbody", "tfoot", "thead", "tr",
-   "td", "th"</dt>
-   <dd>
-    <p><span>Parse error</span>.</p>
-
-    <p>If the <span>stack of open elements</span> does not <span data-x="has an element in table
-    scope">have an element in table scope</span> that is an <span data-x="HTML elements">HTML
-    element</span> with the same tag name as that of the token, then ignore the token.</p>
-
-    <p>Otherwise:</p>
-
-    <!-- fake </select> -->
-    <p>Pop elements from the <span>stack of open elements</span> until a <code>select</code> element
-    has been popped from the stack.</p>
-
-    <p><span>Reset the insertion mode appropriately</span>.</p>
-    <!-- end of fake </select> -->
-
-    <p>Reprocess the token.</p>
-   </dd>
-
-   <dt>Anything else</dt>
-   <dd>
-    <p>Process the token <span>using the rules for</span> the "<span data-x="insertion mode: in
-    select">in select</span>" <span>insertion mode</span>.</p>
-   </dd>
-  </dl>
-
-
-
   <h6 id="parsing-main-intemplate">The "<dfn data-x="insertion mode: in template">in template</dfn>" insertion mode</h6>
 
   <p>When the user agent is to apply the rules for the "<span data-x="insertion mode: in template">in

From b87d93d527aff0fe324e4b6b74a99cdebc0338ed Mon Sep 17 00:00:00 2001
From: Joey Arhar <jarhar@chromium.org>
Date: Wed, 18 Sep 2024 09:52:57 -0700
Subject: [PATCH 02/13] make rules more permissive

---
 source | 60 +++++++++++++---------------------------------------------
 1 file changed, 13 insertions(+), 47 deletions(-)

diff --git a/source b/source
index 22183d6927d..89fd8a970c8 100644
--- a/source
+++ b/source
@@ -129299,22 +129299,8 @@ document.body.appendChild(text);
     element</span>.</p>
 
     <p>If the <span>stack of open elements</span> <span data-x="has an element in scope">has a
-    <code>select</code> element in scope</span> and has either <span data-x="has an element in
-    scope">an <code>option</code> element in scope</span> or <span data-x="has an element in
-    scope">an <code>optgroup</code> element in scope</span>, then:</p>
-
-    <ol>
-     <li><p><span>Generate implied end tags</span> except for <code>option</code> and
-     <code>optgroup</code> elements.</p></li>
-
-     <li><p>If the <span>current node</span> is not now an <code>option</code> or
-     <code>optgroup</code> element, this is a <span>parse error</span>.</p></li>
-
-     <li><p>While the <span>stack of open elements</span> <span data-x="has an element in scope">has
-     an <code>option</code> element in scope</span> or <span data-x="has an element in scope">has an
-     <code>optgroup</code> element in scope</span>, pop an element from the <span>stack of open
-     elements</span>.</p></li>
-    </ol>
+    <code>select</code> element in scope</span>, then <span>generate implied end tags</span> except
+    for <code>option</code> and <code>optgroup</code> elements.</p>
 
     <p><span>Insert an HTML element</span> for the token. Immediately pop the <span>current
     node</span> off the <span>stack of open elements</span>.</p>
@@ -129405,53 +129391,33 @@ document.body.appendChild(text);
    <dt>A start tag whose tag name is "option"</dt>
    <dd>
     <p>If the <span>stack of open elements</span> <span data-x="has an element in scope">has a
-    <code>select</code> element in scope</span> and has a <span data-x="has an element in scope">has
-    an <code>option</code> element in scope</span>, then:</p>
+    <code>select</code> element in scope</span>, then:</p>
 
     <ol>
-     <li><p><span>Generate implied end tags</span> except for <code>option</code> elements.</p></li>
-
-     <li><p>If the <span>current node</span> is not now an <code>option</code> element, this is a
-     <span>parse error</span>.</p></li>
+     <li><p><span>Generate implied end tags</span> except for <code>optgroup</code>
+     elements.</p></li>
 
-     <li><p>While the <span>stack of open elements</span> <span data-x="has an element in scope">has
-     an <code>option</code> element in scope</span>, pop an element from the <span>stack of open
-     elements</span>.</p></li>
+     <li><p>If the <span>stack of open elements</span> <span data-x="has an element in scope">has an
+     <code>option</code> element in scope</span>, then this is a <span>parse error</span>.</p></li>
     </ol>
 
-    <p><span>Reconstruct the active formatting elements</span>, if any.</p>
-
     <p><span>Insert an HTML element</span> for the token.</p>
    </dd>
 
    <dt>A start tag whose tag name is "optgroup"</dt>
    <dd>
     <p>If the <span>stack of open elements</span> <span data-x="has an element in scope">has a
-    <code>select</code> element in scope</span> and has either <span data-x="has an element in
-    scope">an <code>option</code> element in scope</span> or <span data-x="has an element in
-    scope">an <code>optgroup</code> element in scope</span>, then:</p>
+    <code>select</code> element in scope</span>, then:</p>
 
     <ol>
-     <li><p><span>Generate implied end tags</span> except for <code>option</code> and
-     <code>optgroup</code> elements.</p></li>
-
-     <li><p>If the <span>current node</span> is not now an <code>option</code> or
-     <code>optgroup</code> element, this is a <span>parse error</span>.</p></li>
-
-     <li><p><span>Generate implied end tags</span> except for <code>optgroup</code>
-     elements.</p></li>
-
-     <li><p>If the <span>current node</span> is not now an <code>optgroup</code> element, this is a
-     <span>parse error</span>.</p></li>
+     <li><p><span>Generate implied end tags</span>.</p></li>
 
-     <li><p>While the <span>stack of open elements</span> <span data-x="has an element in scope">has
-     an <code>option</code> element in scope</span> or <span data-x="has an element in scope">has an
-     <code>optgroup</code> element in scope</span>, pop an element from the <span>stack of open
-     elements</span>.</p></li>
+     <li><p>If the <span>stack of open elements</span> <span data-x="has an element in scope">has an
+     <code>option</code> element in scope</span> or <span data-x="has an element in scope">has an
+     <code>optgroup</code> element in scope</span>, then this is a <span>parse
+     error</span>.</p></li>
     </ol>
 
-    <p><span>Reconstruct the active formatting elements</span>, if any.</p>
-
     <p><span>Insert an HTML element</span> for the token.</p>
    </dd>
 

From 9c72f6c91ed8a3381809dafb12c2af9006bbcf51 Mon Sep 17 00:00:00 2001
From: Joey Arhar <jarhar@chromium.org>
Date: Fri, 20 Sep 2024 15:32:05 -0700
Subject: [PATCH 03/13] dont allow hr in option

---
 source | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/source b/source
index 89fd8a970c8..bccb692e789 100644
--- a/source
+++ b/source
@@ -129299,8 +129299,15 @@ document.body.appendChild(text);
     element</span>.</p>
 
     <p>If the <span>stack of open elements</span> <span data-x="has an element in scope">has a
-    <code>select</code> element in scope</span>, then <span>generate implied end tags</span> except
-    for <code>option</code> and <code>optgroup</code> elements.</p>
+    <code>select</code> element in scope</span>, then:</p>
+
+    <ol>
+     <li><p><span>Generate implied end tags</span> except for <code>optgroup</code>
+     elements.</p></li>
+
+     <li><p>If the <span>stack of open elements</span> <span data-x="has an element in scope">has an
+     <code>option</code> element in scope</span>, then this is a <span>parse error</span>.</p></li>
+    </ol>
 
     <p><span>Insert an HTML element</span> for the token. Immediately pop the <span>current
     node</span> off the <span>stack of open elements</span>.</p>

From e07cb01a4855cf3942e53a551d7b279300ec9e54 Mon Sep 17 00:00:00 2001
From: Joey Arhar <jarhar@chromium.org>
Date: Wed, 2 Oct 2024 14:05:53 -0700
Subject: [PATCH 04/13] re-add out of select cases

---
 source | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/source b/source
index bccb692e789..80c36b3c2f3 100644
--- a/source
+++ b/source
@@ -129408,6 +129408,9 @@ document.body.appendChild(text);
      <code>option</code> element in scope</span>, then this is a <span>parse error</span>.</p></li>
     </ol>
 
+    <p>Otherwise, if the <span>current node</span> is an <code>option</code> element, then pop the
+    <span>current node</span> off the <span>stack of open elements</span>.</p>
+
     <p><span>Insert an HTML element</span> for the token.</p>
    </dd>
 
@@ -129425,6 +129428,18 @@ document.body.appendChild(text);
      error</span>.</p></li>
     </ol>
 
+    <p>Otherwise:</p>
+
+    <ol>
+     <li><p>If the <span>current node</span> is an <code>option</code> element, and the node
+     immediately before it in the <span>stack of open elements</span> is an <code>optgroup</code>
+     element, then pop the <span>current node</span> from the <span>stack of open
+     elements</span>.</p></li>
+
+     <li><p>If the <span>current node</span> is an <code>optgroup</code> element, then pop that node
+     from the <span>stack of open elements</span>.</p></li>
+    </ol>
+
     <p><span>Insert an HTML element</span> for the token.</p>
    </dd>
 

From 5117d13c8c2f783575ea4ea0837b4d3a266a3ffe Mon Sep 17 00:00:00 2001
From: Joey Arhar <jarhar@chromium.org>
Date: Thu, 3 Oct 2024 09:19:35 -0700
Subject: [PATCH 05/13] re-add reconstruct formatting elements

---
 source | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/source b/source
index 80c36b3c2f3..aa55e950e88 100644
--- a/source
+++ b/source
@@ -129408,8 +129408,14 @@ document.body.appendChild(text);
      <code>option</code> element in scope</span>, then this is a <span>parse error</span>.</p></li>
     </ol>
 
-    <p>Otherwise, if the <span>current node</span> is an <code>option</code> element, then pop the
-    <span>current node</span> off the <span>stack of open elements</span>.</p>
+    <p>Otherwise:</p>
+
+    <ol>
+     <li><p>If the <span>current node</span> is an <code>option</code> element, then pop the
+     <span>current node</span> off the <span>stack of open elements</span>.</p></li>
+
+     <li><p><span>Reconstruct the active formatting elements</span>, if any.</p></li>
+    </ol>
 
     <p><span>Insert an HTML element</span> for the token.</p>
    </dd>
@@ -129438,6 +129444,8 @@ document.body.appendChild(text);
 
      <li><p>If the <span>current node</span> is an <code>optgroup</code> element, then pop that node
      from the <span>stack of open elements</span>.</p></li>
+
+     <li><p><span>Reconstruct the active formatting elements</span>, if any.</p></li>
     </ol>
 
     <p><span>Insert an HTML element</span> for the token.</p>

From 33370b759c686345d7407f1f9855a16e30a8a7bf Mon Sep 17 00:00:00 2001
From: Joey Arhar <jarhar@chromium.org>
Date: Wed, 9 Oct 2024 11:54:32 -0700
Subject: [PATCH 06/13] fix non-select case

---
 source | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/source b/source
index aa55e950e88..508dbe0ae0a 100644
--- a/source
+++ b/source
@@ -129413,8 +129413,6 @@ document.body.appendChild(text);
     <ol>
      <li><p>If the <span>current node</span> is an <code>option</code> element, then pop the
      <span>current node</span> off the <span>stack of open elements</span>.</p></li>
-
-     <li><p><span>Reconstruct the active formatting elements</span>, if any.</p></li>
     </ol>
 
     <p><span>Insert an HTML element</span> for the token.</p>
@@ -129437,15 +129435,11 @@ document.body.appendChild(text);
     <p>Otherwise:</p>
 
     <ol>
-     <li><p>If the <span>current node</span> is an <code>option</code> element, and the node
-     immediately before it in the <span>stack of open elements</span> is an <code>optgroup</code>
-     element, then pop the <span>current node</span> from the <span>stack of open
-     elements</span>.</p></li>
-
-     <li><p>If the <span>current node</span> is an <code>optgroup</code> element, then pop that node
-     from the <span>stack of open elements</span>.</p></li>
+     <li><p>If the <span>current node</span> is an <code>option</code> element, then pop the
+     <span>current node</span> from the <span>stack of open elements</span>.</p></li>
 
-     <li><p><span>Reconstruct the active formatting elements</span>, if any.</p></li>
+     <li><p>If the <span>current node</span> is an <code>optgroup</code> element, then pop the
+     <span>current node</span> from the <span>stack of open elements</span>.</p></li>
     </ol>
 
     <p><span>Insert an HTML element</span> for the token.</p>

From 76e0d7fc12916b84d65de4331da8bb6dc062a16d Mon Sep 17 00:00:00 2001
From: Joey Arhar <jarhar@chromium.org>
Date: Wed, 9 Oct 2024 11:58:51 -0700
Subject: [PATCH 07/13] fix variable names

---
 source | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/source b/source
index 508dbe0ae0a..5f5607a04fe 100644
--- a/source
+++ b/source
@@ -54150,12 +54150,12 @@ interface <dfn interface>HTMLOptionElement</dfn> : <span>HTMLElement</span> {
 
   <ol>
    <li>
-    <p>For each <var>ancestor</var> of <var>option</var>'s <span
+    <p>For each <var>ancestor</var> of <var>insertedOption</var>'s <span
     data-x="ancestor">ancestors</span>:</p>
 
     <ol>
      <li><p>If <var>ancestor</var> is a <code>select</code> element, then run the <span>selectedness
-     setting algorithm</span> given <var>select</var> and return.</p></li>
+     setting algorithm</span> given <var>ancestor</var> and return.</p></li>
     </ol>
    </li>
   </ol>
@@ -54170,7 +54170,7 @@ interface <dfn interface>HTMLOptionElement</dfn> : <span>HTMLElement</span> {
 
     <ol>
      <li><p>If <var>ancestor</var> is a <code>select</code> element, then run the <span>selectedness
-     setting algorithm</span> given <var>select</var> and return.</p></li>
+     setting algorithm</span> given <var>ancestor</var> and return.</p></li>
     </ol>
   </ol>
 

From 58b9ca95af7ff8290b706fd8a15f497a2fbf418e Mon Sep 17 00:00:00 2001
From: Joey Arhar <jarhar@chromium.org>
Date: Thu, 10 Oct 2024 15:24:29 -0700
Subject: [PATCH 08/13] re-add reconstruct active formatting elements

---
 source | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/source b/source
index 5f5607a04fe..4012a654300 100644
--- a/source
+++ b/source
@@ -129413,6 +129413,8 @@ document.body.appendChild(text);
     <ol>
      <li><p>If the <span>current node</span> is an <code>option</code> element, then pop the
      <span>current node</span> off the <span>stack of open elements</span>.</p></li>
+
+     <li><p><span>Reconstruct the active formatting elements</span>, if any.</p></li>
     </ol>
 
     <p><span>Insert an HTML element</span> for the token.</p>
@@ -129440,6 +129442,8 @@ document.body.appendChild(text);
 
      <li><p>If the <span>current node</span> is an <code>optgroup</code> element, then pop the
      <span>current node</span> from the <span>stack of open elements</span>.</p></li>
+
+     <li><p><span>Reconstruct the active formatting elements</span>, if any.</p></li>
     </ol>
 
     <p><span>Insert an HTML element</span> for the token.</p>

From b8ba8e6440876480dcfce31f412e1c3376bd5613 Mon Sep 17 00:00:00 2001
From: Joey Arhar <jarhar@chromium.org>
Date: Thu, 10 Oct 2024 15:47:27 -0700
Subject: [PATCH 09/13] remove pop optgroup

---
 source | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/source b/source
index 4012a654300..53215090d69 100644
--- a/source
+++ b/source
@@ -129440,9 +129440,6 @@ document.body.appendChild(text);
      <li><p>If the <span>current node</span> is an <code>option</code> element, then pop the
      <span>current node</span> from the <span>stack of open elements</span>.</p></li>
 
-     <li><p>If the <span>current node</span> is an <code>optgroup</code> element, then pop the
-     <span>current node</span> from the <span>stack of open elements</span>.</p></li>
-
      <li><p><span>Reconstruct the active formatting elements</span>, if any.</p></li>
     </ol>
 

From c37560ab2b1182c52d4f47b8c20356542701b406 Mon Sep 17 00:00:00 2001
From: Joey Arhar <jarhar@chromium.org>
Date: Thu, 21 Nov 2024 13:19:15 -0800
Subject: [PATCH 10/13] Always reconstruct formatting context

---
 source | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/source b/source
index 53215090d69..804d345536b 100644
--- a/source
+++ b/source
@@ -129413,10 +129413,10 @@ document.body.appendChild(text);
     <ol>
      <li><p>If the <span>current node</span> is an <code>option</code> element, then pop the
      <span>current node</span> off the <span>stack of open elements</span>.</p></li>
-
-     <li><p><span>Reconstruct the active formatting elements</span>, if any.</p></li>
     </ol>
 
+    <p><span>Reconstruct the active formatting elements</span>, if any.</p>
+
     <p><span>Insert an HTML element</span> for the token.</p>
    </dd>
 
@@ -129434,14 +129434,10 @@ document.body.appendChild(text);
      error</span>.</p></li>
     </ol>
 
-    <p>Otherwise:</p>
+    <p>Otherwise, if the <span>current node</span> is an <code>option</code> element, then pop the
+    <span>current node</span> from the <span>stack of open elements</span>.</p>
 
-    <ol>
-     <li><p>If the <span>current node</span> is an <code>option</code> element, then pop the
-     <span>current node</span> from the <span>stack of open elements</span>.</p></li>
-
-     <li><p><span>Reconstruct the active formatting elements</span>, if any.</p></li>
-    </ol>
+    <p><span>Reconstruct the active formatting elements</span>, if any.</p>
 
     <p><span>Insert an HTML element</span> for the token.</p>
    </dd>

From e615f9bb2728899114b87c23c30b280f06763f63 Mon Sep 17 00:00:00 2001
From: Joey Arhar <jarhar@chromium.org>
Date: Thu, 21 Nov 2024 13:30:26 -0800
Subject: [PATCH 11/13] fix hr generate implied end tags

---
 source | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/source b/source
index 804d345536b..98df2684fd2 100644
--- a/source
+++ b/source
@@ -129302,11 +129302,12 @@ document.body.appendChild(text);
     <code>select</code> element in scope</span>, then:</p>
 
     <ol>
-     <li><p><span>Generate implied end tags</span> except for <code>optgroup</code>
-     elements.</p></li>
+     <li><p><span>Generate implied end tags</span>.<p></li>
 
      <li><p>If the <span>stack of open elements</span> <span data-x="has an element in scope">has an
-     <code>option</code> element in scope</span>, then this is a <span>parse error</span>.</p></li>
+     <code>option</code> element in scope</span> or <span data-x="has an element in scope">has an
+     <code>optgroup</code> element in scope</span>, then this is a <span>parse
+     error</span>.</p></li>
     </ol>
 
     <p><span>Insert an HTML element</span> for the token. Immediately pop the <span>current

From 53fa2f49328cc1dc07216e027b37f40438be79eb Mon Sep 17 00:00:00 2001
From: Joey Arhar <jarhar@chromium.org>
Date: Thu, 21 Nov 2024 13:33:07 -0800
Subject: [PATCH 12/13] in reverse tree order

---
 source | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/source b/source
index 98df2684fd2..3f1599dd069 100644
--- a/source
+++ b/source
@@ -54151,7 +54151,7 @@ interface <dfn interface>HTMLOptionElement</dfn> : <span>HTMLElement</span> {
   <ol>
    <li>
     <p>For each <var>ancestor</var> of <var>insertedOption</var>'s <span
-    data-x="ancestor">ancestors</span>:</p>
+    data-x="ancestor">ancestors</span> in reverse <span>tree order</span>:</p>
 
     <ol>
      <li><p>If <var>ancestor</var> is a <code>select</code> element, then run the <span>selectedness
@@ -54166,7 +54166,7 @@ interface <dfn interface>HTMLOptionElement</dfn> : <span>HTMLElement</span> {
   <ol>
    <li>
     <p>For each <var>ancestor</var> of <var>oldParent</var>'s <span data-x="inclusive
-    ancestor">inclusive ancestors</span>:</p>
+    ancestor">inclusive ancestors</span> in reverse <span>tree order</span>:</p>
 
     <ol>
      <li><p>If <var>ancestor</var> is a <code>select</code> element, then run the <span>selectedness

From 5c0627dd258647c279d1e563c260df68a08fbf9c Mon Sep 17 00:00:00 2001
From: Joey Arhar <jarhar@chromium.org>
Date: Thu, 21 Nov 2024 13:37:45 -0800
Subject: [PATCH 13/13] <select><select>

---
 source | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/source b/source
index 3f1599dd069..35d0eef0686 100644
--- a/source
+++ b/source
@@ -129389,11 +129389,15 @@ document.body.appendChild(text);
      element has been popped from the stack.</p></li>
     </ol>
 
-    <p><span>Reconstruct the active formatting elements</span>, if any.</p>
+    <p>Otherwise:</p>
 
-    <p><span>Insert an HTML element</span> for the token.</p>
+    <ol>
+     <li><p><span>Reconstruct the active formatting elements</span>, if any.</p></li>
 
-    <p>Set the <span>frameset-ok flag</span> to "not ok".</p>
+     <li><p><span>Insert an HTML element</span> for the token.</p></li>
+
+     <li><p>Set the <span>frameset-ok flag</span> to "not ok".</p></li>
+    </ol>
    </dd>
 
    <dt>A start tag whose tag name is "option"</dt>