Remove HTML 4 support (#11385)

author: Adam Turner <9087854+AA-Turner@users.noreply.github.com> 2023-04-28 11:32:12 +0100
committer: GitHub <noreply@github.com> 2023-04-28 11:32:12 +0100
commit: ad473730a3763f241e9aaea1a87d1893f01b86fd (patch)
tree: 84da748a87f2b4c3f2274a770697bb322a718578
parent: 3e3251d3ba4f1e5fa6d34d995505f4d3ace5acad (diff)
download: sphinx-git-ad473730a3763f241e9aaea1a87d1893f01b86fd.tar.gz
5 files changed, 25 insertions, 899 deletions
diff --git a/sphinx/builders/html/__init__.py b/sphinx/builders/html/__init__.py
index cd6e9498e..8b8c426a4 100644
--- a/sphinx/builders/html/__init__.py
+++ b/sphinx/builders/html/__init__.py
@@ -45,7 +45,6 @@ from sphinx.util.inventory import InventoryFile
 from sphinx.util.matching import DOTFILES, Matcher, patmatch
 from sphinx.util.osutil import copyfile, ensuredir, os_path, relative_uri
 from sphinx.util.tags import Tags
-from sphinx.writers._html4 import HTML4Translator
 from sphinx.writers.html import HTMLWriter
 from sphinx.writers.html5 import HTML5Translator
 
@@ -374,10 +373,7 @@ class StandaloneHTMLBuilder(Builder):
 
     @property
     def default_translator_class(self) -> type[nodes.NodeVisitor]:  # type: ignore
-        if self.config.html4_writer:
-            return HTML4Translator  # RemovedInSphinx70Warning
-        else:
-            return HTML5Translator
+        return HTML5Translator
 
     @property
     def math_renderer_name(self) -> str:
@@ -565,7 +561,7 @@ class StandaloneHTMLBuilder(Builder):
             'parents': [],
             'logo_url': logo,
             'favicon_url': favicon,
-            'html5_doctype': not self.config.html4_writer,
+            'html5_doctype': True,
         }
         if self.theme:
             self.globalcontext.update(
@@ -1310,13 +1306,13 @@ def validate_html_favicon(app: Sphinx, config: Config) -> None:
         config.html_favicon = None  # type: ignore
 
 
-def deprecate_html_4(_app: Sphinx, config: Config) -> None:
-    """Warn on HTML 4."""
-    # RemovedInSphinx70Warning
+def error_on_html_4(_app: Sphinx, config: Config) -> None:
+    """Error on HTML 4."""
     if config.html4_writer:
-        logger.warning(_('Support for emitting HTML 4 output is deprecated and '
-                         'will be removed in Sphinx 7. ("html4_writer=True" '
-                         'detected in configuration options)'))
+        raise ConfigError(_(
+            'HTML 4 is no longer supported by Sphinx. '
+            '("html4_writer=True" detected in configuration options)',
+        ))
 
 
 def setup(app: Sphinx) -> dict[str, Any]:
@@ -1380,7 +1376,7 @@ def setup(app: Sphinx) -> dict[str, Any]:
     app.connect('config-inited', validate_html_static_path, priority=800)
     app.connect('config-inited', validate_html_logo, priority=800)
     app.connect('config-inited', validate_html_favicon, priority=800)
-    app.connect('config-inited', deprecate_html_4, priority=800)
+    app.connect('config-inited', error_on_html_4, priority=800)
     app.connect('builder-inited', validate_math_renderer)
     app.connect('html-page-context', setup_css_tag_helper)
     app.connect('html-page-context', setup_js_tag_helper)
diff --git a/sphinx/themes/basic/layout.html b/sphinx/themes/basic/layout.html
index 6e9096a1d..f3088f79a 100644
--- a/sphinx/themes/basic/layout.html
+++ b/sphinx/themes/basic/layout.html
@@ -7,12 +7,9 @@
     :copyright: Copyright 2007-2023 by the Sphinx team, see AUTHORS.
     :license: BSD, see LICENSE for details.
 #}
-{%- block doctype -%}{%- if html5_doctype %}
+{%- block doctype -%}
 <!DOCTYPE html>
-{%- else %}
-<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
-  "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
-{%- endif %}{%- endblock %}
+{%- endblock %}
 {%- set reldelim1 = reldelim1 is not defined and ' &#187;' or reldelim1 %}
 {%- set reldelim2 = reldelim2 is not defined and ' |' or reldelim2 %}
 {%- set render_sidebar = (not embedded) and (not theme_nosidebar|tobool) and
@@ -105,17 +102,10 @@
 {%- if html_tag %}
 {{ html_tag }}
 {%- else %}
-<html{% if not html5_doctype %} xmlns="http://www.w3.org/1999/xhtml"{% endif %}{% if language is not none %} lang="{{ language }}"{% endif %}>
+<html{% if language is not none %} lang="{{ language }}"{% endif %}>
 {%- endif %}
   <head>
-    {%- if not html5_doctype and not skip_ua_compatible %}
-    <meta http-equiv="X-UA-Compatible" content="IE=Edge" />
-    {%- endif %}
-    {%- if use_meta_charset or html5_doctype %}
     <meta charset="{{ encoding }}" />
-    {%- else %}
-    <meta http-equiv="Content-Type" content="text/html; charset={{ encoding }}" />
-    {%- endif %}
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     {{- metatags }}
     {%- block htmltitle %}
diff --git a/sphinx/writers/_html4.py b/sphinx/writers/_html4.py
deleted file mode 100644
index 0b670bf99..000000000
--- a/sphinx/writers/_html4.py
+++ /dev/null
@@ -1,857 +0,0 @@
-"""Frozen HTML 4 translator."""
-
-from __future__ import annotations
-
-import os
-import posixpath
-import re
-import urllib.parse
-from typing import TYPE_CHECKING, Iterable, cast
-
-from docutils import nodes
-from docutils.nodes import Element, Node, Text
-from docutils.writers.html4css1 import HTMLTranslator as BaseTranslator
-
-from sphinx import addnodes
-from sphinx.builders import Builder
-from sphinx.locale import _, __, admonitionlabels
-from sphinx.util import logging
-from sphinx.util.docutils import SphinxTranslator
-from sphinx.util.images import get_image_size
-
-if TYPE_CHECKING:
-    from sphinx.builders.html import StandaloneHTMLBuilder
-
-
-logger = logging.getLogger(__name__)
-
-
-def multiply_length(length: str, scale: int) -> str:
-    """Multiply *length* (width or height) by *scale*."""
-    matched = re.match(r'^(\d*\.?\d*)\s*(\S*)$', length)
-    if not matched:
-        return length
-    if scale == 100:
-        return length
-    amount, unit = matched.groups()
-    result = float(amount) * scale / 100
-    return f"{int(result)}{unit}"
-
-
-# RemovedInSphinx70Warning
-class HTML4Translator(SphinxTranslator, BaseTranslator):
-    """
-    Our custom HTML translator.
-    """
-
-    builder: StandaloneHTMLBuilder
-
-    def __init__(self, document: nodes.document, builder: Builder) -> None:
-        super().__init__(document, builder)
-
-        self.highlighter = self.builder.highlighter
-        self.docnames = [self.builder.current_docname]  # for singlehtml builder
-        self.manpages_url = self.config.manpages_url
-        self.protect_literal_text = 0
-        self.secnumber_suffix = self.config.html_secnumber_suffix
-        self.param_separator = ''
-        self.optional_param_level = 0
-        self._table_row_indices = [0]
-        self._fieldlist_row_indices = [0]
-        self.required_params_left = 0
-
-    def visit_start_of_file(self, node: Element) -> None:
-        # only occurs in the single-file builder
-        self.docnames.append(node['docname'])
-        self.body.append('<span id="document-%s"></span>' % node['docname'])
-
-    def depart_start_of_file(self, node: Element) -> None:
-        self.docnames.pop()
-
-    #############################################################
-    # Domain-specific object descriptions
-    #############################################################
-
-    # Top-level nodes for descriptions
-    ##################################
-
-    def visit_desc(self, node: Element) -> None:
-        self.body.append(self.starttag(node, 'dl'))
-
-    def depart_desc(self, node: Element) -> None:
-        self.body.append('</dl>\n\n')
-
-    def visit_desc_signature(self, node: Element) -> None:
-        # the id is set automatically
-        self.body.append(self.starttag(node, 'dt'))
-        self.protect_literal_text += 1
-
-    def depart_desc_signature(self, node: Element) -> None:
-        self.protect_literal_text -= 1
-        if not node.get('is_multiline'):
-            self.add_permalink_ref(node, _('Permalink to this definition'))
-        self.body.append('</dt>\n')
-
-    def visit_desc_signature_line(self, node: Element) -> None:
-        pass
-
-    def depart_desc_signature_line(self, node: Element) -> None:
-        if node.get('add_permalink'):
-            # the permalink info is on the parent desc_signature node
-            self.add_permalink_ref(node.parent, _('Permalink to this definition'))
-        self.body.append('<br />')
-
-    def visit_desc_content(self, node: Element) -> None:
-        self.body.append(self.starttag(node, 'dd', ''))
-
-    def depart_desc_content(self, node: Element) -> None:
-        self.body.append('</dd>')
-
-    def visit_desc_inline(self, node: Element) -> None:
-        self.body.append(self.starttag(node, 'span', ''))
-
-    def depart_desc_inline(self, node: Element) -> None:
-        self.body.append('</span>')
-
-    # Nodes for high-level structure in signatures
-    ##############################################
-
-    def visit_desc_name(self, node: Element) -> None:
-        self.body.append(self.starttag(node, 'code', ''))
-
-    def depart_desc_name(self, node: Element) -> None:
-        self.body.append('</code>')
-
-    def visit_desc_addname(self, node: Element) -> None:
-        self.body.append(self.starttag(node, 'code', ''))
-
-    def depart_desc_addname(self, node: Element) -> None:
-        self.body.append('</code>')
-
-    def visit_desc_type(self, node: Element) -> None:
-        pass
-
-    def depart_desc_type(self, node: Element) -> None:
-        pass
-
-    def visit_desc_returns(self, node: Element) -> None:
-        self.body.append(' <span class="sig-return">')
-        self.body.append('<span class="sig-return-icon">&#x2192;</span>')
-        self.body.append(' <span class="sig-return-typehint">')
-
-    def depart_desc_returns(self, node: Element) -> None:
-        self.body.append('</span></span>')
-
-    def visit_desc_parameterlist(self, node: Element) -> None:
-        self.body.append('<span class="sig-paren">(</span>')
-        self.first_param = 1
-        self.optional_param_level = 0
-        # How many required parameters are left.
-        self.required_params_left = sum([isinstance(c, addnodes.desc_parameter)
-                                         for c in node.children])
-        self.param_separator = node.child_text_separator
-
-    def depart_desc_parameterlist(self, node: Element) -> None:
-        self.body.append('<span class="sig-paren">)</span>')
-
-    # If required parameters are still to come, then put the comma after
-    # the parameter.  Otherwise, put the comma before.  This ensures that
-    # signatures like the following render correctly (see issue #1001):
-    #
-    #     foo([a, ]b, c[, d])
-    #
-    def visit_desc_parameter(self, node: Element) -> None:
-        if self.first_param:
-            self.first_param = 0
-        elif not self.required_params_left:
-            self.body.append(self.param_separator)
-        if self.optional_param_level == 0:
-            self.required_params_left -= 1
-        if not node.hasattr('noemph'):
-            self.body.append('<em>')
-
-    def depart_desc_parameter(self, node: Element) -> None:
-        if not node.hasattr('noemph'):
-            self.body.append('</em>')
-        if self.required_params_left:
-            self.body.append(self.param_separator)
-
-    def visit_desc_optional(self, node: Element) -> None:
-        self.optional_param_level += 1
-        self.body.append('<span class="optional">[</span>')
-
-    def depart_desc_optional(self, node: Element) -> None:
-        self.optional_param_level -= 1
-        self.body.append('<span class="optional">]</span>')
-
-    def visit_desc_annotation(self, node: Element) -> None:
-        self.body.append(self.starttag(node, 'em', '', CLASS='property'))
-
-    def depart_desc_annotation(self, node: Element) -> None:
-        self.body.append('</em>')
-
-    ##############################################
-
-    def visit_versionmodified(self, node: Element) -> None:
-        self.body.append(self.starttag(node, 'div', CLASS=node['type']))
-
-    def depart_versionmodified(self, node: Element) -> None:
-        self.body.append('</div>\n')
-
-    # overwritten
-    def visit_reference(self, node: Element) -> None:
-        atts = {'class': 'reference'}
-        if node.get('internal') or 'refuri' not in node:
-            atts['class'] += ' internal'
-        else:
-            atts['class'] += ' external'
-        if 'refuri' in node:
-            atts['href'] = node['refuri'] or '#'
-            if self.settings.cloak_email_addresses and atts['href'].startswith('mailto:'):
-                atts['href'] = self.cloak_mailto(atts['href'])
-                self.in_mailto = True
-        else:
-            assert 'refid' in node, \
-                   'References must have "refuri" or "refid" attribute.'
-            atts['href'] = '#' + node['refid']
-        if not isinstance(node.parent, nodes.TextElement):
-            assert len(node) == 1 and isinstance(node[0], nodes.image)  # NoQA: PT018
-            atts['class'] += ' image-reference'
-        if 'reftitle' in node:
-            atts['title'] = node['reftitle']
-        if 'target' in node:
-            atts['target'] = node['target']
-        self.body.append(self.starttag(node, 'a', '', **atts))
-
-        if node.get('secnumber'):
-            self.body.append(('%s' + self.secnumber_suffix) %
-                             '.'.join(map(str, node['secnumber'])))
-
-    def visit_number_reference(self, node: Element) -> None:
-        self.visit_reference(node)
-
-    def depart_number_reference(self, node: Element) -> None:
-        self.depart_reference(node)
-
-    # overwritten -- we don't want source comments to show up in the HTML
-    def visit_comment(self, node: Element) -> None:  # type: ignore
-        raise nodes.SkipNode
-
-    # overwritten
-    def visit_admonition(self, node: Element, name: str = '') -> None:
-        self.body.append(self.starttag(
-            node, 'div', CLASS=('admonition ' + name)))
-        if name:
-            node.insert(0, nodes.title(name, admonitionlabels[name]))
-        self.set_first_last(node)
-
-    def depart_admonition(self, node: Element | None = None) -> None:
-        self.body.append('</div>\n')
-
-    def visit_seealso(self, node: Element) -> None:
-        self.visit_admonition(node, 'seealso')
-
-    def depart_seealso(self, node: Element) -> None:
-        self.depart_admonition(node)
-
-    def get_secnumber(self, node: Element) -> tuple[int, ...] | None:
-        if node.get('secnumber'):
-            return node['secnumber']
-        elif isinstance(node.parent, nodes.section):
-            if self.builder.name == 'singlehtml':
-                docname = self.docnames[-1]
-                anchorname = f"{docname}/#{node.parent['ids'][0]}"
-                if anchorname not in self.builder.secnumbers:
-                    anchorname = "%s/" % docname  # try first heading which has no anchor
-            else:
-                anchorname = '#' + node.parent['ids'][0]
-                if anchorname not in self.builder.secnumbers:
-                    anchorname = ''  # try first heading which has no anchor
-
-            if self.builder.secnumbers.get(anchorname):
-                return self.builder.secnumbers[anchorname]
-
-        return None
-
-    def add_secnumber(self, node: Element) -> None:
-        secnumber = self.get_secnumber(node)
-        if secnumber:
-            self.body.append('<span class="section-number">%s</span>' %
-                             ('.'.join(map(str, secnumber)) + self.secnumber_suffix))
-
-    def add_fignumber(self, node: Element) -> None:
-        def append_fignumber(figtype: str, figure_id: str) -> None:
-            if self.builder.name == 'singlehtml':
-                key = f"{self.docnames[-1]}/{figtype}"
-            else:
-                key = figtype
-
-            if figure_id in self.builder.fignumbers.get(key, {}):
-                self.body.append('<span class="caption-number">')
-                prefix = self.config.numfig_format.get(figtype)
-                if prefix is None:
-                    msg = __('numfig_format is not defined for %s') % figtype
-                    logger.warning(msg)
-                else:
-                    numbers = self.builder.fignumbers[key][figure_id]
-                    self.body.append(prefix % '.'.join(map(str, numbers)) + ' ')
-                    self.body.append('</span>')
-
-        figtype = self.builder.env.domains['std'].get_enumerable_node_type(node)
-        if figtype:
-            if len(node['ids']) == 0:
-                msg = __('Any IDs not assigned for %s node') % node.tagname
-                logger.warning(msg, location=node)
-            else:
-                append_fignumber(figtype, node['ids'][0])
-
-    def add_permalink_ref(self, node: Element, title: str) -> None:
-        if node['ids'] and self.config.html_permalinks and self.builder.add_permalinks:
-            format = '<a class="headerlink" href="#%s" title="%s">%s</a>'
-            self.body.append(format % (node['ids'][0], title,
-                                       self.config.html_permalinks_icon))
-
-    def generate_targets_for_listing(self, node: Element) -> None:
-        """Generate hyperlink targets for listings.
-
-        Original visit_bullet_list(), visit_definition_list() and visit_enumerated_list()
-        generates hyperlink targets inside listing tags (<ul>, <ol> and <dl>) if multiple
-        IDs are assigned to listings.  That is invalid DOM structure.
-        (This is a bug of docutils <= 0.12)
-
-        This exports hyperlink targets before listings to make valid DOM structure.
-        """
-        for id in node['ids'][1:]:
-            self.body.append('<span id="%s"></span>' % id)
-            node['ids'].remove(id)
-
-    # overwritten
-    def visit_bullet_list(self, node: Element) -> None:
-        if len(node) == 1 and isinstance(node[0], addnodes.toctree):
-            # avoid emitting empty <ul></ul>
-            raise nodes.SkipNode
-        self.generate_targets_for_listing(node)
-        super().visit_bullet_list(node)
-
-    # overwritten
-    def visit_enumerated_list(self, node: Element) -> None:
-        self.generate_targets_for_listing(node)
-        super().visit_enumerated_list(node)
-
-    # overwritten
-    def visit_definition(self, node: Element) -> None:
-        # don't insert </dt> here.
-        self.body.append(self.starttag(node, 'dd', ''))
-
-    # overwritten
-    def depart_definition(self, node: Element) -> None:
-        self.body.append('</dd>\n')
-
-    # overwritten
-    def visit_classifier(self, node: Element) -> None:
-        self.body.append(self.starttag(node, 'span', '', CLASS='classifier'))
-
-    # overwritten
-    def depart_classifier(self, node: Element) -> None:
-        self.body.append('</span>')
-
-        next_node: Node = node.next_node(descend=False, siblings=True)
-        if not isinstance(next_node, nodes.classifier):
-            # close `<dt>` tag at the tail of classifiers
-            self.body.append('</dt>')
-
-    # overwritten
-    def visit_term(self, node: Element) -> None:
-        self.body.append(self.starttag(node, 'dt', ''))
-
-    # overwritten
-    def depart_term(self, node: Element) -> None:
-        next_node: Node = node.next_node(descend=False, siblings=True)
-        if isinstance(next_node, nodes.classifier):
-            # Leave the end tag to `self.depart_classifier()`, in case
-            # there's a classifier.
-            pass
-        else:
-            if isinstance(node.parent.parent.parent, addnodes.glossary):
-                # add permalink if glossary terms
-                self.add_permalink_ref(node, _('Permalink to this term'))
-
-            self.body.append('</dt>')
-
-    # overwritten
-    def visit_title(self, node: Element) -> None:
-        if isinstance(node.parent, addnodes.compact_paragraph) and node.parent.get('toctree'):
-            self.body.append(self.starttag(node, 'p', '', CLASS='caption', ROLE='heading'))
-            self.body.append('<span class="caption-text">')
-            self.context.append('</span></p>\n')
-        else:
-            super().visit_title(node)
-        self.add_secnumber(node)
-        self.add_fignumber(node.parent)
-        if isinstance(node.parent, nodes.table):
-            self.body.append('<span class="caption-text">')
-
-    def depart_title(self, node: Element) -> None:
-        close_tag = self.context[-1]
-        if (self.config.html_permalinks and self.builder.add_permalinks and
-           node.parent.hasattr('ids') and node.parent['ids']):
-            # add permalink anchor
-            if close_tag.startswith('</h'):
-                self.add_permalink_ref(node.parent, _('Permalink to this heading'))
-            elif close_tag.startswith('</a></h'):
-                self.body.append('</a><a class="headerlink" href="#%s" ' %
-                                 node.parent['ids'][0] +
-                                 'title="{}">{}'.format(
-                                     _('Permalink to this heading'),
-                                     self.config.html_permalinks_icon))
-            elif isinstance(node.parent, nodes.table):
-                self.body.append('</span>')
-                self.add_permalink_ref(node.parent, _('Permalink to this table'))
-        elif isinstance(node.parent, nodes.table):
-            self.body.append('</span>')
-
-        super().depart_title(node)
-
-    # overwritten
-    def visit_literal_block(self, node: Element) -> None:
-        if node.rawsource != node.astext():
-            # most probably a parsed-literal block -- don't highlight
-            return super().visit_literal_block(node)
-
-        lang = node.get('language', 'default')
-        linenos = node.get('linenos', False)
-        highlight_args = node.get('highlight_args', {})
-        highlight_args['force'] = node.get('force', False)
-        opts = self.config.highlight_options.get(lang, {})
-
-        if linenos and self.config.html_codeblock_linenos_style:
-            linenos = self.config.html_codeblock_linenos_style
-
-        highlighted = self.highlighter.highlight_block(
-            node.rawsource, lang, opts=opts, linenos=linenos,
-            location=node, **highlight_args,
-        )
-        starttag = self.starttag(node, 'div', suffix='',
-                                 CLASS='highlight-%s notranslate' % lang)
-        self.body.append(starttag + highlighted + '</div>\n')
-        raise nodes.SkipNode
-
-    def visit_caption(self, node: Element) -> None:
-        if isinstance(node.parent, nodes.container) and node.parent.get('literal_block'):
-            self.body.append('<div class="code-block-caption">')
-        else:
-            super().visit_caption(node)
-        self.add_fignumber(node.parent)
-        self.body.append(self.starttag(node, 'span', '', CLASS='caption-text'))
-
-    def depart_caption(self, node: Element) -> None:
-        self.body.append('</span>')
-
-        # append permalink if available
-        if isinstance(node.parent, nodes.container) and node.parent.get('literal_block'):
-            self.add_permalink_ref(node.parent, _('Permalink to this code'))
-        elif isinstance(node.parent, nodes.figure):
-            self.add_permalink_ref(node.parent, _('Permalink to this image'))
-        elif node.parent.get('toctree'):
-            self.add_permalink_ref(node.parent.parent, _('Permalink to this toctree'))
-
-        if isinstance(node.parent, nodes.container) and node.parent.get('literal_block'):
-            self.body.append('</div>\n')
-        else:
-            super().depart_caption(node)
-
-    def visit_doctest_block(self, node: Element) -> None:
-        self.visit_literal_block(node)
-
-    # overwritten to add the <div> (for XHTML compliance)
-    def visit_block_quote(self, node: Element) -> None:
-        self.body.append(self.starttag(node, 'blockquote') + '<div>')
-
-    def depart_block_quote(self, node: Element) -> None:
-        self.body.append('</div></blockquote>\n')
-
-    # overwritten
-    def visit_literal(self, node: Element) -> None:
-        if 'kbd' in node['classes']:
-            self.body.append(self.starttag(node, 'kbd', '',
-                                           CLASS='docutils literal notranslate'))
-            return
-        lang = node.get("language", None)
-        if 'code' not in node['classes'] or not lang:
-            self.body.append(self.starttag(node, 'code', '',
-                                           CLASS='docutils literal notranslate'))
-            self.protect_literal_text += 1
-            return
-
-        opts = self.config.highlight_options.get(lang, {})
-        highlighted = self.highlighter.highlight_block(
-            node.astext(), lang, opts=opts, location=node, nowrap=True)
-        starttag = self.starttag(
-            node,
-            "code",
-            suffix="",
-            CLASS="docutils literal highlight highlight-%s" % lang,
-        )
-        self.body.append(starttag + highlighted.strip() + "</code>")
-        raise nodes.SkipNode
-
-    def depart_literal(self, node: Element) -> None:
-        if 'kbd' in node['classes']:
-            self.body.append('</kbd>')
-        else:
-            self.protect_literal_text -= 1
-            self.body.append('</code>')
-
-    def visit_productionlist(self, node: Element) -> None:
-        self.body.append(self.starttag(node, 'pre'))
-        names = []
-        productionlist = cast(Iterable[addnodes.production], node)
-        for production in productionlist:
-            names.append(production['tokenname'])
-        maxlen = max(len(name) for name in names)
-        lastname = None
-        for production in productionlist:
-            if production['tokenname']:
-                lastname = production['tokenname'].ljust(maxlen)
-                self.body.append(self.starttag(production, 'strong', ''))
-                self.body.append(lastname + '</strong> ::= ')
-            elif lastname is not None:
-                self.body.append('%s     ' % (' ' * len(lastname)))
-            production.walkabout(self)
-            self.body.append('\n')
-        self.body.append('</pre>\n')
-        raise nodes.SkipNode
-
-    def depart_productionlist(self, node: Element) -> None:
-        pass
-
-    def visit_production(self, node: Element) -> None:
-        pass
-
-    def depart_production(self, node: Element) -> None:
-        pass
-
-    def visit_centered(self, node: Element) -> None:
-        self.body.append(self.starttag(node, 'p', CLASS="centered") +
-                         '<strong>')
-
-    def depart_centered(self, node: Element) -> None:
-        self.body.append('</strong></p>')
-
-    # overwritten
-    def should_be_compact_paragraph(self, node: Node) -> bool:
-        """Determine if the <p> tags around paragraph can be omitted."""
-        if isinstance(node.parent, addnodes.desc_content):
-            # Never compact desc_content items.
-            return False
-        if isinstance(node.parent, addnodes.versionmodified):
-            # Never compact versionmodified nodes.
-            return False
-        return super().should_be_compact_paragraph(node)
-
-    def visit_compact_paragraph(self, node: Element) -> None:
-        pass
-
-    def depart_compact_paragraph(self, node: Element) -> None:
-        pass
-
-    def visit_download_reference(self, node: Element) -> None:
-        atts = {'class': 'reference download',
-                'download': ''}
-
-        if not self.builder.download_support:
-            self.context.append('')
-        elif 'refuri' in node:
-            atts['class'] += ' external'
-            atts['href'] = node['refuri']
-            self.body.append(self.starttag(node, 'a', '', **atts))
-            self.context.append('</a>')
-        elif 'filename' in node:
-            atts['class'] += ' internal'
-            atts['href'] = posixpath.join(self.builder.dlpath,
-                                          urllib.parse.quote(node['filename']))
-            self.body.append(self.starttag(node, 'a', '', **atts))
-            self.context.append('</a>')
-        else:
-            self.context.append('')
-
-    def depart_download_reference(self, node: Element) -> None:
-        self.body.append(self.context.pop())
-
-    # overwritten
-    def visit_figure(self, node: Element) -> None:
-        # set align=default if align not specified to give a default style
-        node.setdefault('align', 'default')
-
-        return super().visit_figure(node)
-
-    # overwritten
-    def visit_image(self, node: Element) -> None:
-        olduri = node['uri']
-        # rewrite the URI if the environment knows about it
-        if olduri in self.builder.images:
-            node['uri'] = posixpath.join(self.builder.imgpath,
-                                         urllib.parse.quote(self.builder.images[olduri]))
-
-        if 'scale' in node:
-            # Try to figure out image height and width.  Docutils does that too,
-            # but it tries the final file name, which does not necessarily exist
-            # yet at the time the HTML file is written.
-            if not ('width' in node and 'height' in node):
-                size = get_image_size(os.path.join(self.builder.srcdir, olduri))
-                if size is None:
-                    logger.warning(
-                        __('Could not obtain image size. :scale: option is ignored.'),
-                        location=node,
-                    )
-                else:
-                    if 'width' not in node:
-                        node['width'] = str(size[0])
-                    if 'height' not in node:
-                        node['height'] = str(size[1])
-
-        uri = node['uri']
-        if uri.lower().endswith(('svg', 'svgz')):
-            atts = {'src': uri}
-            if 'width' in node:
-                atts['width'] = node['width']
-            if 'height' in node:
-                atts['height'] = node['height']
-            if 'scale' in node:
-                if 'width' in atts:
-                    atts['width'] = multiply_length(atts['width'], node['scale'])
-                if 'height' in atts:
-                    atts['height'] = multiply_length(atts['height'], node['scale'])
-            atts['alt'] = node.get('alt', uri)
-            if 'align' in node:
-                atts['class'] = 'align-%s' % node['align']
-            self.body.append(self.emptytag(node, 'img', '', **atts))
-            return
-
-        super().visit_image(node)
-
-    # overwritten
-    def depart_image(self, node: Element) -> None:
-        if node['uri'].lower().endswith(('svg', 'svgz')):
-            pass
-        else:
-            super().depart_image(node)
-
-    def visit_toctree(self, node: Element) -> None:
-        # this only happens when formatting a toc from env.tocs -- in this
-        # case we don't want to include the subtree
-        raise nodes.SkipNode
-
-    def visit_index(self, node: Element) -> None:
-        raise nodes.SkipNode
-
-    def visit_tabular_col_spec(self, node: Element) -> None:
-        raise nodes.SkipNode
-
-    def visit_glossary(self, node: Element) -> None:
-        pass
-
-    def depart_glossary(self, node: Element) -> None:
-        pass
-
-    def visit_acks(self, node: Element) -> None:
-        pass
-
-    def depart_acks(self, node: Element) -> None:
-        pass
-
-    def visit_hlist(self, node: Element) -> None:
-        self.body.append('<table class="hlist"><tr>')
-
-    def depart_hlist(self, node: Element) -> None:
-        self.body.append('</tr></table>\n')
-
-    def visit_hlistcol(self, node: Element) -> None:
-        self.body.append('<td>')
-
-    def depart_hlistcol(self, node: Element) -> None:
-        self.body.append('</td>')
-
-    def visit_option_group(self, node: Element) -> None:
-        super().visit_option_group(node)
-        self.context[-2] = self.context[-2].replace('&nbsp;', '&#160;')
-
-    # overwritten
-    def visit_Text(self, node: Text) -> None:
-        text = node.astext()
-        encoded = self.encode(text)
-        if self.protect_literal_text:
-            # moved here from base class's visit_literal to support
-            # more formatting in literal nodes
-            for token in self.words_and_spaces.findall(encoded):
-                if token.strip():
-                    # protect literal text from line wrapping
-                    self.body.append('<span class="pre">%s</span>' % token)
-                elif token in ' \n':
-                    # allow breaks at whitespace
-                    self.body.append(token)
-                else:
-                    # protect runs of multiple spaces; the last one can wrap
-                    self.body.append('&#160;' * (len(token) - 1) + ' ')
-        else:
-            if self.in_mailto and self.settings.cloak_email_addresses:
-                encoded = self.cloak_email(encoded)
-            self.body.append(encoded)
-
-    def visit_note(self, node: Element) -> None:
-        self.visit_admonition(node, 'note')
-
-    def depart_note(self, node: Element) -> None:
-        self.depart_admonition(node)
-
-    def visit_warning(self, node: Element) -> None:
-        self.visit_admonition(node, 'warning')
-
-    def depart_warning(self, node: Element) -> None:
-        self.depart_admonition(node)
-
-    def visit_attention(self, node: Element) -> None:
-        self.visit_admonition(node, 'attention')
-
-    def depart_attention(self, node: Element) -> None:
-        self.depart_admonition(node)
-
-    def visit_caution(self, node: Element) -> None:
-        self.visit_admonition(node, 'caution')
-
-    def depart_caution(self, node: Element) -> None:
-        self.depart_admonition(node)
-
-    def visit_danger(self, node: Element) -> None:
-        self.visit_admonition(node, 'danger')
-
-    def depart_danger(self, node: Element) -> None:
-        self.depart_admonition(node)
-
-    def visit_error(self, node: Element) -> None:
-        self.visit_admonition(node, 'error')
-
-    def depart_error(self, node: Element) -> None:
-        self.depart_admonition(node)
-
-    def visit_hint(self, node: Element) -> None:
-        self.visit_admonition(node, 'hint')
-
-    def depart_hint(self, node: Element) -> None:
-        self.depart_admonition(node)
-
-    def visit_important(self, node: Element) -> None:
-        self.visit_admonition(node, 'important')
-
-    def depart_important(self, node: Element) -> None:
-        self.depart_admonition(node)
-
-    def visit_tip(self, node: Element) -> None:
-        self.visit_admonition(node, 'tip')
-
-    def depart_tip(self, node: Element) -> None:
-        self.depart_admonition(node)
-
-    def visit_literal_emphasis(self, node: Element) -> None:
-        return self.visit_emphasis(node)
-
-    def depart_literal_emphasis(self, node: Element) -> None:
-        return self.depart_emphasis(node)
-
-    def visit_literal_strong(self, node: Element) -> None:
-        return self.visit_strong(node)
-
-    def depart_literal_strong(self, node: Element) -> None:
-        return self.depart_strong(node)
-
-    def visit_abbreviation(self, node: Element) -> None:
-        attrs = {}
-        if node.hasattr('explanation'):
-            attrs['title'] = node['explanation']
-        self.body.append(self.starttag(node, 'abbr', '', **attrs))
-
-    def depart_abbreviation(self, node: Element) -> None:
-        self.body.append('</abbr>')
-
-    def visit_manpage(self, node: Element) -> None:
-        self.visit_literal_emphasis(node)
-        if self.manpages_url:
-            node['refuri'] = self.manpages_url.format(**node.attributes)
-            self.visit_reference(node)
-
-    def depart_manpage(self, node: Element) -> None:
-        if self.manpages_url:
-            self.depart_reference(node)
-        self.depart_literal_emphasis(node)
-
-    # overwritten to add even/odd classes
-
-    def visit_table(self, node: Element) -> None:
-        self._table_row_indices.append(0)
-
-        # set align=default if align not specified to give a default style
-        node.setdefault('align', 'default')
-
-        return super().visit_table(node)
-
-    def depart_table(self, node: Element) -> None:
-        self._table_row_indices.pop()
-        super().depart_table(node)
-
-    def visit_row(self, node: Element) -> None:
-        self._table_row_indices[-1] += 1
-        if self._table_row_indices[-1] % 2 == 0:
-            node['classes'].append('row-even')
-        else:
-            node['classes'].append('row-odd')
-        self.body.append(self.starttag(node, 'tr', ''))
-        node.column = 0  # type: ignore
-
-    def visit_entry(self, node: Element) -> None:
-        super().visit_entry(node)
-        if self.body[-1] == '&nbsp;':
-            self.body[-1] = '&#160;'
-
-    def visit_field_list(self, node: Element) -> None:
-        self._fieldlist_row_indices.append(0)
-        return super().visit_field_list(node)
-
-    def depart_field_list(self, node: Element) -> None:
-        self._fieldlist_row_indices.pop()
-        return super().depart_field_list(node)
-
-    def visit_field(self, node: Element) -> None:
-        self._fieldlist_row_indices[-1] += 1
-        if self._fieldlist_row_indices[-1] % 2 == 0:
-            node['classes'].append('field-even')
-        else:
-            node['classes'].append('field-odd')
-        self.body.append(self.starttag(node, 'tr', '', CLASS='field'))
-
-    def visit_field_name(self, node: Element) -> None:
-        context_count = len(self.context)
-        super().visit_field_name(node)
-        if context_count != len(self.context):
-            self.context[-1] = self.context[-1].replace('&nbsp;', '&#160;')
-
-    def visit_math(self, node: Element, math_env: str = '') -> None:
-        name = self.builder.math_renderer_name
-        visit, _ = self.builder.app.registry.html_inline_math_renderers[name]
-        visit(self, node)
-
-    def depart_math(self, node: Element, math_env: str = '') -> None:
-        name = self.builder.math_renderer_name
-        _, depart = self.builder.app.registry.html_inline_math_renderers[name]
-        if depart:  # type: ignore[truthy-function]
-            depart(self, node)
-
-    def visit_math_block(self, node: Element, math_env: str = '') -> None:
-        name = self.builder.math_renderer_name
-        visit, _ = self.builder.app.registry.html_block_math_renderers[name]
-        visit(self, node)
-
-    def depart_math_block(self, node: Element, math_env: str = '') -> None:
-        name = self.builder.math_renderer_name
-        _, depart = self.builder.app.registry.html_block_math_renderers[name]
-        if depart:  # type: ignore[truthy-function]
-            depart(self, node)
diff --git a/sphinx/writers/html.py b/sphinx/writers/html.py
index faa8d8ad8..198e03508 100644
--- a/sphinx/writers/html.py
+++ b/sphinx/writers/html.py
@@ -7,15 +7,14 @@ from typing import TYPE_CHECKING, cast
 from docutils.writers.html4css1 import Writer
 
 from sphinx.util import logging
-from sphinx.writers._html4 import HTML4Translator
-from sphinx.writers.html5 import HTML5Translator  # NoQA: F401
+from sphinx.writers.html5 import HTML5Translator
 
 if TYPE_CHECKING:
     from sphinx.builders.html import StandaloneHTMLBuilder
 
 
 logger = logging.getLogger(__name__)
-HTMLTranslator = HTML4Translator
+HTMLTranslator = HTML5Translator
 
 # A good overview of the purpose behind these classes can be found here:
 # http://www.arnebrodowski.de/blog/write-your-own-restructuredtext-writer.html
@@ -33,7 +32,7 @@ class HTMLWriter(Writer):
     def translate(self) -> None:
         # sadly, this is mostly copied from parent class
         visitor = self.builder.create_translator(self.document, self.builder)
-        self.visitor = cast(HTML4Translator, visitor)
+        self.visitor = cast(HTML5Translator, visitor)
         self.document.walkabout(visitor)
         self.output = self.visitor.astext()
         for attr in ('head_prefix', 'stylesheet', 'head', 'body_prefix',
diff --git a/tests/test_build_html.py b/tests/test_build_html.py
index 013c09bdb..8591897fb 100644
--- a/tests/test_build_html.py
+++ b/tests/test_build_html.py
@@ -123,19 +123,17 @@ def test_html_warnings(app, warning):
         '--- Got:\n' + html_warnings
 
 
-@pytest.mark.sphinx('html', confoverrides={'html4_writer': True})
-def test_html4_output(app, status, warning):
-    app.build()
-
-
-def test_html4_deprecation(make_app, tempdir):
+def test_html4_error(make_app, tempdir):
     (tempdir / 'conf.py').write_text('', encoding='utf-8')
-    app = make_app(
-        buildername='html',
-        srcdir=tempdir,
-        confoverrides={'html4_writer': True},
-    )
-    assert 'HTML 4 output is deprecated and will be removed' in app._warning.getvalue()
+    with pytest.raises(
+        ConfigError,
+        match=r'HTML 4 is no longer supported by Sphinx',
+    ):
+        make_app(
+            buildername='html',
+            srcdir=tempdir,
+            confoverrides={'html4_writer': True},
+        )
 
 
 @pytest.mark.parametrize("fname,expect", flat_dict({
author	Adam Turner <9087854+AA-Turner@users.noreply.github.com>	2023-04-28 11:32:12 +0100
committer	GitHub <noreply@github.com>	2023-04-28 11:32:12 +0100
commit	ad473730a3763f241e9aaea1a87d1893f01b86fd (patch)
tree	84da748a87f2b4c3f2274a770697bb322a718578
parent	3e3251d3ba4f1e5fa6d34d995505f4d3ace5acad (diff)
download	sphinx-git-ad473730a3763f241e9aaea1a87d1893f01b86fd.tar.gz