From d9e3a6262dbe57fb519b959ccf1a134debc01dc6 Mon Sep 17 00:00:00 2001
From: Anne van Kesteren <annevk@annevk.nl>
Date: Wed, 3 May 2023 01:13:46 -0700
Subject: [PATCH] HTML parser: allow <hr> to be used inside <select> as a
 separator https://bugs.webkit.org/show_bug.cgi?id=80686 rdar://107656886

Reviewed by Ryosuke Niwa.

Revive support in the HTML parser for <hr>-in-<select>, thereby making an existing UI feature much more accessible to web developers.

This reflects a recent change in the HTML Standard: https://github.com/whatwg/html/pull/9124.

* LayoutTests/html5lib/resources/webkit02.dat:

These are being upstreamed via https://github.com/html5lib/html5lib-tests/pull/167 and will then be incorporated into web-platform-tests.

* Source/WebCore/html/parser/HTMLTreeBuilder.cpp:
(WebCore::HTMLTreeBuilder::processStartTag):

Canonical link: https://commits.webkit.org/263624@main
---
 LayoutTests/html5lib/resources/webkit02.dat   | 132 ++++++++++++++++++
 .../WebCore/html/parser/HTMLTreeBuilder.cpp   |   7 +
 2 files changed, 139 insertions(+)
diff --git a/LayoutTests/html5lib/resources/webkit02.dat b/LayoutTests/html5lib/resources/webkit02.dat
index b232fa792750a..b5fd9a9623bde 100644
--- a/LayoutTests/html5lib/resources/webkit02.dat
+++ b/LayoutTests/html5lib/resources/webkit02.dat
@@ -235,3 +235,135 @@ select
 |   <body>
 |     <math math>
 |       definitionURL=""
+
+#data
+<select><hr>
+#errors
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <hr>
+
+#data
+<select><option><hr>
+#errors
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <option>
+|       <hr>
+
+#data
+<select><optgroup><option><hr>
+#errors
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <optgroup>
+|         <option>
+|       <hr>
+
+#data
+<select><optgroup><hr>
+#errors
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <optgroup>
+|       <hr>
+
+#data
+<select><option><optgroup><hr>
+#errors
+#document
+| <html>
+|   <head>
+|   <body>
+|     <select>
+|       <option>
+|       <optgroup>
+|       <hr>
+
+#data
+<table><tr><td><select><hr>
+#errors
+#document
+| <html>
+|   <head>
+|   <body>
+|     <table>
+|       <tbody>
+|         <tr>
+|           <td>
+|             <select>
+|               <hr>
+
+#data
+<table><tr><td><select><option><hr>
+#errors
+#document
+| <html>
+|   <head>
+|   <body>
+|     <table>
+|       <tbody>
+|         <tr>
+|           <td>
+|             <select>
+|               <option>
+|               <hr>
+
+#data
+<table><tr><td><select><optgroup><option><hr>
+#errors
+#document
+| <html>
+|   <head>
+|   <body>
+|     <table>
+|       <tbody>
+|         <tr>
+|           <td>
+|             <select>
+|               <optgroup>
+|                 <option>
+|               <hr>
+
+#data
+<table><tr><td><select><optgroup><hr>
+#errors
+#document
+| <html>
+|   <head>
+|   <body>
+|     <table>
+|       <tbody>
+|         <tr>
+|           <td>
+|             <select>
+|               <optgroup>
+|               <hr>
+
+#data
+<table><tr><td><select><option><optgroup><hr>
+#errors
+#document
+| <html>
+|   <head>
+|   <body>
+|     <table>
+|       <tbody>
+|         <tr>
+|           <td>
+|             <select>
+|               <option>
+|               <optgroup>
+|               <hr>
diff --git a/Source/WebCore/html/parser/HTMLTreeBuilder.cpp b/Source/WebCore/html/parser/HTMLTreeBuilder.cpp
index 1f43ac2e90340..1bd547426e0b9 100644
--- a/Source/WebCore/html/parser/HTMLTreeBuilder.cpp
+++ b/Source/WebCore/html/parser/HTMLTreeBuilder.cpp
@@ -1424,6 +1424,13 @@ void HTMLTreeBuilder::processStartTag(AtomHTMLToken&& token)
                 processFakeEndTag(TagName::optgroup);
             m_tree.insertHTMLElement(WTFMove(token));
             return;
+        case TagName::hr:
+            if (m_tree.currentStackItem().elementName() == HTML::option)
+                processFakeEndTag(TagName::option);
+            if (m_tree.currentStackItem().elementName() == HTML::optgroup)
+                processFakeEndTag(TagName::optgroup);
+            m_tree.insertSelfClosingHTMLElement(WTFMove(token));
+            return;
         case TagName::select: {
             parseError(token);
             AtomHTMLToken endSelect(HTMLToken::Type::EndTag, TagName::select);
