From c621b718415fe9b378dd3897d48762c7a30d9e12 Mon Sep 17 00:00:00 2001
From: Adam Turner <9087854+AA-Turner@users.noreply.github.com>
Date: Sun, 17 Apr 2022 04:36:20 +0100
Subject: [PATCH] Increase minimum Docutils to 0.17

---
 .github/workflows/main.yml            |  4 +-
 pyproject.toml                        |  2 +-
 sphinx/addnodes.py                    | 17 +-----
 sphinx/directives/patches.py          | 41 +++++++-------
 sphinx/transforms/__init__.py         | 13 ++---
 sphinx/transforms/i18n.py             |  2 +-
 sphinx/util/docutils.py               |  2 +-
 sphinx/util/nodes.py                  | 22 +------
 tests/test_api_translator.py          |  6 +-
 tests/test_build_html.py              | 18 ++----
 tests/test_ext_graphviz.py            | 82 +++++++++------------------
 tests/test_ext_inheritance_diagram.py | 67 +++++++---------------
 tests/test_intl.py                    | 17 ++----
 tests/test_markup.py                  |  3 -
 tox.ini                               |  7 +--
 15 files changed, 93 insertions(+), 210 deletions(-)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index d88c10ab6dd..08fb55c8568 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -14,9 +14,9 @@ jobs:
       matrix:
         include:
         - python: "3.8"
-          docutils: du16
-        - python: "3.9"
           docutils: du17
+        - python: "3.9"
+          docutils: du18
         - python: "3.10"
           docutils: du18
         - python: "3.10"
diff --git a/pyproject.toml b/pyproject.toml
index 1e09d178d5f..5d53f412a63 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -62,7 +62,7 @@ dependencies = [
     "sphinxcontrib-qthelp",
     "Jinja2>=3.0",
     "Pygments>=2.12",
-    "docutils>=0.14,<0.20",
+    "docutils>=0.17,<0.20",
     "snowballstemmer>=2.0",
     "babel>=2.9",
     "alabaster>=0.7,<0.8",
diff --git a/sphinx/addnodes.py b/sphinx/addnodes.py
index e22ce5fa20e..4abddf2057f 100644
--- a/sphinx/addnodes.py
+++ b/sphinx/addnodes.py
@@ -12,7 +12,7 @@
 try:
     from docutils.nodes import meta as docutils_meta  # type: ignore
 except ImportError:
-    # docutils-0.17 or older
+    # docutils-0.17
     from docutils.parsers.rst.directives.html import MetaBody
     docutils_meta = MetaBody.meta
 
@@ -29,18 +29,7 @@ class document(nodes.document):
 
     def set_id(self, node: Element, msgnode: Optional[Element] = None,
                suggested_prefix: str = '') -> str:
-        if docutils.__version_info__ >= (0, 16):
-            ret = super().set_id(node, msgnode, suggested_prefix)  # type: ignore
-        else:
-            ret = super().set_id(node, msgnode)
-
-        if docutils.__version_info__ < (0, 17):
-            # register other node IDs forcedly
-            for node_id in node['ids']:
-                if node_id not in self.ids:
-                    self.ids[node_id] = node
-
-        return ret
+        return super().set_id(node, msgnode, suggested_prefix)  # type: ignore
 
 
 class translatable(nodes.Node):
@@ -198,7 +187,7 @@ class desc_inline(_desc_classes_injector, nodes.Inline, nodes.TextElement):
     classes = ['sig', 'sig-inline']
 
     def __init__(self, domain: str, *args: Any, **kwargs: Any) -> None:
-        super().__init__(*args, **kwargs)
+        super().__init__(*args, **kwargs, domain=domain)
         self['classes'].append(domain)
 
 
diff --git a/sphinx/directives/patches.py b/sphinx/directives/patches.py
index 876683ad0c6..a0bf2626206 100644
--- a/sphinx/directives/patches.py
+++ b/sphinx/directives/patches.py
@@ -19,11 +19,29 @@
 from sphinx.util.typing import OptionSpec
 
 try:
-    from docutils.parsers.rst.directives.misc import Meta as MetaBase  # type: ignore
+    from docutils.parsers.rst.directives.misc import Meta as Meta  # type: ignore
 except ImportError:
-    # docutils-0.17 or older
+    # docutils-0.17
     from docutils.parsers.rst.directives.html import Meta as MetaBase
 
+    class Meta(MetaBase, SphinxDirective):  # type: ignore
+        def run(self) -> Sequence[Node]:  # type: ignore
+            result = super().run()
+            for node in result:
+                # for docutils-0.17.  Since docutils-0.18, patching is no longer needed
+                # because it uses picklable node; ``docutils.nodes.meta``.
+                if (isinstance(node, nodes.pending) and
+                        isinstance(node.details['nodes'][0], addnodes.docutils_meta)):
+                    meta = node.details['nodes'][0]
+                    meta.source = self.env.doc2path(self.env.docname)
+                    meta.line = self.lineno
+                    meta.rawcontent = meta['content']
+
+                    # docutils' meta nodes aren't picklable because the class is nested
+                    meta.__class__ = addnodes.meta
+
+            return result
+
 if TYPE_CHECKING:
     from sphinx.application import Sphinx
 
@@ -57,25 +75,6 @@ def run(self) -> List[Node]:
         return [figure_node]
 
 
-class Meta(MetaBase, SphinxDirective):
-    def run(self) -> Sequence[Node]:
-        result = super().run()
-        for node in result:
-            # for docutils-0.17 or older.  Since docutils-0.18, patching is no longer needed
-            # because it uses picklable node; ``docutils.nodes.meta``.
-            if (isinstance(node, nodes.pending) and
-               isinstance(node.details['nodes'][0], addnodes.docutils_meta)):
-                meta = node.details['nodes'][0]
-                meta.source = self.env.doc2path(self.env.docname)
-                meta.line = self.lineno
-                meta.rawcontent = meta['content']
-
-                # docutils' meta nodes aren't picklable because the class is nested
-                meta.__class__ = addnodes.meta
-
-        return result
-
-
 class CSVTable(tables.CSVTable):
     """The csv-table directive which searches a CSV file from Sphinx project's source
     directory when an absolute path is given via :file: option.
diff --git a/sphinx/transforms/__init__.py b/sphinx/transforms/__init__.py
index 2d6a027e319..9ca95a73fca 100644
--- a/sphinx/transforms/__init__.py
+++ b/sphinx/transforms/__init__.py
@@ -4,7 +4,6 @@
 import unicodedata
 from typing import TYPE_CHECKING, Any, Dict, Generator, List, Optional, Tuple, cast
 
-import docutils
 from docutils import nodes
 from docutils.nodes import Element, Node, Text
 from docutils.transforms import Transform, Transformer
@@ -342,16 +341,12 @@ def get_tokens(self, txtnodes: List[Text]) -> Generator[Tuple[str, str], None, N
         # of "Text" nodes (interface to ``smartquotes.educate_tokens()``).
         for txtnode in txtnodes:
             if is_smartquotable(txtnode):
-                if docutils.__version_info__ >= (0, 16):
-                    # SmartQuotes uses backslash escapes instead of null-escapes
-                    text = re.sub(r'(?<=\x00)([-\\\'".`])', r'\\\1', str(txtnode))
-                else:
-                    text = txtnode.astext()
-
-                yield ('plain', text)
+                # SmartQuotes uses backslash escapes instead of null-escapes
+                text = re.sub(r'(?<=\x00)([-\\\'".`])', r'\\\1', str(txtnode))
+                yield 'plain', text
             else:
                 # skip smart quotes
-                yield ('literal', txtnode.astext())
+                yield 'literal', txtnode.astext()
 
 
 class DoctreeReadEvent(SphinxTransform):
diff --git a/sphinx/transforms/i18n.py b/sphinx/transforms/i18n.py
index 160c7f35d24..fd32f0dc17d 100644
--- a/sphinx/transforms/i18n.py
+++ b/sphinx/transforms/i18n.py
@@ -255,7 +255,7 @@ def apply(self, **kwargs: Any) -> None:
 
             # update meta nodes
             if isinstance(node, nodes.pending) and is_pending_meta(node):
-                # docutils-0.17 or older
+                # docutils-0.17
                 node.details['nodes'][0]['content'] = msgstr
                 continue
             elif isinstance(node, addnodes.docutils_meta):
diff --git a/sphinx/util/docutils.py b/sphinx/util/docutils.py
index cde09058e4d..63c9a06efc9 100644
--- a/sphinx/util/docutils.py
+++ b/sphinx/util/docutils.py
@@ -591,7 +591,7 @@ def unknown_visit(self, node: Node) -> None:
 # Node.findall() is a new interface to traverse a doctree since docutils-0.18.
 # This applies a patch to docutils up to 0.18 inclusive to provide Node.findall()
 # method to use it from our codebase.
-if docutils.__version_info__ <= (0, 18):
+if docutils.__version_info__[:2] <= (0, 17):
     def findall(self, *args, **kwargs):
         return iter(self.traverse(*args, **kwargs))
 
diff --git a/sphinx/util/nodes.py b/sphinx/util/nodes.py
index 0646b44e642..fdbf94fe659 100644
--- a/sphinx/util/nodes.py
+++ b/sphinx/util/nodes.py
@@ -226,7 +226,7 @@ def is_translatable(node: Node) -> bool:
         return True
 
     if is_pending_meta(node) or isinstance(node, addnodes.meta):
-        # docutils-0.17 or older
+        # docutils-0.17
         return True
     elif isinstance(node, addnodes.docutils_meta):
         # docutils-0.18+
@@ -268,10 +268,10 @@ def extract_messages(doctree: Element) -> Iterable[Tuple[Element, str]]:
             else:
                 msg = ''
         elif isinstance(node, META_TYPE_NODES):
-            # docutils-0.17 or older
+            # docutils-0.17
             msg = node.rawcontent
         elif isinstance(node, nodes.pending) and is_pending_meta(node):
-            # docutils-0.17 or older
+            # docutils-0.17
             msg = node.details['nodes'][0].rawcontent
         elif isinstance(node, addnodes.docutils_meta):
             # docutils-0.18+
@@ -625,19 +625,3 @@ def process_only_nodes(document: Node, tags: "Tags") -> None:
                 # the only node, so we make sure docutils can transfer the id to
                 # something, even if it's just a comment and will lose the id anyway...
                 node.replace_self(nodes.comment())
-
-
-def _new_copy(self: Element) -> Element:
-    """monkey-patch Element.copy to copy the rawsource and line
-    for docutils-0.16 or older versions.
-
-    refs: https://sourceforge.net/p/docutils/patches/165/
-    """
-    newnode = self.__class__(self.rawsource, **self.attributes)
-    if isinstance(self, nodes.Element):
-        newnode.source = self.source
-        newnode.line = self.line
-    return newnode
-
-
-nodes.Element.copy = _new_copy  # type: ignore
diff --git a/tests/test_api_translator.py b/tests/test_api_translator.py
index 25aee0c6126..2185fb8db1b 100644
--- a/tests/test_api_translator.py
+++ b/tests/test_api_translator.py
@@ -2,7 +2,6 @@
 
 import sys
 
-import docutils
 import pytest
 
 
@@ -19,10 +18,7 @@ def test_html_translator(app, status, warning):
     # no set_translator()
     translator_class = app.builder.get_translator_class()
     assert translator_class
-    if docutils.__version_info__ < (0, 13):
-        assert translator_class.__name__ == 'HTMLTranslator'
-    else:
-        assert translator_class.__name__ == 'HTML5Translator'
+    assert translator_class.__name__ == 'HTML5Translator'
 
 
 @pytest.mark.sphinx('html', testroot='api-set-translator')
diff --git a/tests/test_build_html.py b/tests/test_build_html.py
index 072f187ba99..10fdbdf79f6 100644
--- a/tests/test_build_html.py
+++ b/tests/test_build_html.py
@@ -15,10 +15,7 @@
 from sphinx.util import md5
 from sphinx.util.inventory import InventoryFile
 
-if docutils.__version_info__ < (0, 17):
-    FIGURE_CAPTION = ".//div[@class='figure align-default']/p[@class='caption']"
-else:
-    FIGURE_CAPTION = ".//figure/figcaption/p"
+FIGURE_CAPTION = ".//figure/figcaption/p"
 
 
 ENV_WARNINGS = """\
@@ -442,7 +439,7 @@ def test_docutils17_output(app, cached_etree_parse, fname, expect):
     check_xpath(cached_etree_parse(app.outdir / fname), fname, *expect)
 
 
-@pytest.mark.skipif(docutils.__version_info__ < (0, 18), reason='docutils-0.18+ is required.')
+@pytest.mark.skipif(docutils.__version_info__[:2] <= (0, 17), reason='docutils-0.18+ is required.')
 @pytest.mark.parametrize("fname,expect", flat_dict({
     'index.html': [
         (".//div[@class='citation']/span", r'Ref1'),
@@ -1324,14 +1321,9 @@ def test_html_inventory(app):
 def test_html_anchor_for_figure(app):
     app.builder.build_all()
     content = (app.outdir / 'index.html').read_text(encoding='utf8')
-    if docutils.__version_info__ < (0, 17):
-        assert ('<p class="caption"><span class="caption-text">The caption of pic</span>'
-                '<a class="headerlink" href="#id1" title="Permalink to this image">¶</a></p>'
-                in content)
-    else:
-        assert ('<figcaption>\n<p><span class="caption-text">The caption of pic</span>'
-                '<a class="headerlink" href="#id1" title="Permalink to this image">¶</a></p>\n</figcaption>'
-                in content)
+    assert ('<figcaption>\n<p><span class="caption-text">The caption of pic</span>'
+            '<a class="headerlink" href="#id1" title="Permalink to this image">¶</a></p>\n</figcaption>'
+            in content)
 
 
 @pytest.mark.sphinx('html', testroot='directives-raw')
diff --git a/tests/test_ext_graphviz.py b/tests/test_ext_graphviz.py
index 649cf1861a5..28591674b1e 100644
--- a/tests/test_ext_graphviz.py
+++ b/tests/test_ext_graphviz.py
@@ -2,7 +2,6 @@
 
 import re
 
-import docutils
 import pytest
 
 from sphinx.ext.graphviz import ClickableMapDefinition
@@ -14,15 +13,10 @@ def test_graphviz_png_html(app, status, warning):
     app.builder.build_all()
 
     content = (app.outdir / 'index.html').read_text(encoding='utf8')
-    if docutils.__version_info__ < (0, 17):
-        html = (r'<div class="figure align-default" .*?>\s*'
-                r'<div class="graphviz"><img .*?/></div>\s*<p class="caption">'
-                r'<span class="caption-text">caption of graph</span>.*</p>\s*</div>')
-    else:
-        html = (r'<figure class="align-default" .*?>\s*'
-                r'<div class="graphviz"><img .*?/></div>\s*<figcaption>\s*'
-                r'<p><span class="caption-text">caption of graph</span>.*</p>\s*'
-                r'</figcaption>\s*</figure>')
+    html = (r'<figure class="align-default" .*?>\s*'
+            r'<div class="graphviz"><img .*?/></div>\s*<figcaption>\s*'
+            r'<p><span class="caption-text">caption of graph</span>.*</p>\s*'
+            r'</figcaption>\s*</figure>')
     assert re.search(html, content, re.S)
 
     html = 'Hello <div class="graphviz"><img .*?/></div>\n graphviz world'
@@ -32,15 +26,10 @@ def test_graphviz_png_html(app, status, warning):
             'class="graphviz neato-graph" />')
     assert re.search(html, content, re.S)
 
-    if docutils.__version_info__ < (0, 17):
-        html = (r'<div class="figure align-right" .*?>\s*'
-                r'<div class="graphviz"><img .*?/></div>\s*<p class="caption">'
-                r'<span class="caption-text">on <em>right</em></span>.*</p>\s*</div>')
-    else:
-        html = (r'<figure class="align-right" .*?>\s*'
-                r'<div class="graphviz"><img .*?/></div>\s*<figcaption>\s*'
-                r'<p><span class="caption-text">on <em>right</em></span>.*</p>\s*'
-                r'</figcaption>\s*</figure>')
+    html = (r'<figure class="align-right" .*?>\s*'
+            r'<div class="graphviz"><img .*?/></div>\s*<figcaption>\s*'
+            r'<p><span class="caption-text">on <em>right</em></span>.*</p>\s*'
+            r'</figcaption>\s*</figure>')
     assert re.search(html, content, re.S)
 
     html = (r'<div align=\"center\" class=\"align-center\">'
@@ -58,24 +47,15 @@ def test_graphviz_svg_html(app, status, warning):
 
     content = (app.outdir / 'index.html').read_text(encoding='utf8')
 
-    if docutils.__version_info__ < (0, 17):
-        html = (r'<div class=\"figure align-default\" .*?>\n'
-                r'<div class="graphviz"><object data=\".*\.svg\".*>\n'
-                r'\s*<p class=\"warning\">digraph foo {\n'
-                r'bar -&gt; baz\n'
-                r'}</p></object></div>\n'
-                r'<p class=\"caption\"><span class=\"caption-text\">'
-                r'caption of graph</span>.*</p>\n</div>')
-    else:
-        html = (r'<figure class=\"align-default\" .*?>\n'
-                r'<div class="graphviz"><object data=\".*\.svg\".*>\n'
-                r'\s*<p class=\"warning\">digraph foo {\n'
-                r'bar -&gt; baz\n'
-                r'}</p></object></div>\n'
-                r'<figcaption>\n'
-                r'<p><span class=\"caption-text\">caption of graph</span>.*</p>\n'
-                r'</figcaption>\n'
-                r'</figure>')
+    html = (r'<figure class=\"align-default\" .*?>\n'
+            r'<div class="graphviz"><object data=\".*\.svg\".*>\n'
+            r'\s*<p class=\"warning\">digraph foo {\n'
+            r'bar -&gt; baz\n'
+            r'}</p></object></div>\n'
+            r'<figcaption>\n'
+            r'<p><span class=\"caption-text\">caption of graph</span>.*</p>\n'
+            r'</figcaption>\n'
+            r'</figure>')
     assert re.search(html, content, re.S)
 
     html = (r'Hello <div class="graphviz"><object.*>\n'
@@ -83,25 +63,15 @@ def test_graphviz_svg_html(app, status, warning):
             r' graphviz world')
     assert re.search(html, content, re.S)
 
-    if docutils.__version_info__ < (0, 17):
-        html = (r'<div class=\"figure align-right\" .*\>\n'
-                r'<div class="graphviz"><object data=\".*\.svg\".*>\n'
-                r'\s*<p class=\"warning\">digraph bar {\n'
-                r'foo -&gt; bar\n'
-                r'}</p></object></div>\n'
-                r'<p class=\"caption\"><span class=\"caption-text\">'
-                r'on <em>right</em></span>.*</p>\n'
-                r'</div>')
-    else:
-        html = (r'<figure class=\"align-right\" .*\>\n'
-                r'<div class="graphviz"><object data=\".*\.svg\".*>\n'
-                r'\s*<p class=\"warning\">digraph bar {\n'
-                r'foo -&gt; bar\n'
-                r'}</p></object></div>\n'
-                r'<figcaption>\n'
-                r'<p><span class=\"caption-text\">on <em>right</em></span>.*</p>\n'
-                r'</figcaption>\n'
-                r'</figure>')
+    html = (r'<figure class=\"align-right\" .*\>\n'
+            r'<div class="graphviz"><object data=\".*\.svg\".*>\n'
+            r'\s*<p class=\"warning\">digraph bar {\n'
+            r'foo -&gt; bar\n'
+            r'}</p></object></div>\n'
+            r'<figcaption>\n'
+            r'<p><span class=\"caption-text\">on <em>right</em></span>.*</p>\n'
+            r'</figcaption>\n'
+            r'</figure>')
     assert re.search(html, content, re.S)
 
     html = (r'<div align=\"center\" class=\"align-center\">'
diff --git a/tests/test_ext_inheritance_diagram.py b/tests/test_ext_inheritance_diagram.py
index 4f99ef5da94..7b1ea2b569c 100644
--- a/tests/test_ext_inheritance_diagram.py
+++ b/tests/test_ext_inheritance_diagram.py
@@ -4,7 +4,6 @@
 import re
 import sys
 
-import docutils
 import pytest
 
 from sphinx.ext.inheritance_diagram import (InheritanceDiagram, InheritanceException,
@@ -140,20 +139,12 @@ def test_inheritance_diagram_png_html(app, status, warning):
 
     content = (app.outdir / 'index.html').read_text(encoding='utf8')
 
-    if docutils.__version_info__ < (0, 17):
-        pattern = ('<div class="figure align-default" id="id1">\n'
-                   '<div class="graphviz">'
-                   '<img src="_images/inheritance-\\w+.png" alt="Inheritance diagram of test.Foo" '
-                   'class="inheritance graphviz" /></div>\n<p class="caption">'
-                   '<span class="caption-text">Test Foo!</span><a class="headerlink" href="#id1" '
-                   'title="Permalink to this image">\xb6</a></p>\n</div>\n')
-    else:
-        pattern = ('<figure class="align-default" id="id1">\n'
-                   '<div class="graphviz">'
-                   '<img src="_images/inheritance-\\w+.png" alt="Inheritance diagram of test.Foo" '
-                   'class="inheritance graphviz" /></div>\n<figcaption>\n<p>'
-                   '<span class="caption-text">Test Foo!</span><a class="headerlink" href="#id1" '
-                   'title="Permalink to this image">\xb6</a></p>\n</figcaption>\n</figure>\n')
+    pattern = ('<figure class="align-default" id="id1">\n'
+               '<div class="graphviz">'
+               '<img src="_images/inheritance-\\w+.png" alt="Inheritance diagram of test.Foo" '
+               'class="inheritance graphviz" /></div>\n<figcaption>\n<p>'
+               '<span class="caption-text">Test Foo!</span><a class="headerlink" href="#id1" '
+               'title="Permalink to this image">\xb6</a></p>\n</figcaption>\n</figure>\n')
     assert re.search(pattern, content, re.M)
 
 
@@ -165,24 +156,14 @@ def test_inheritance_diagram_svg_html(app, status, warning):
 
     content = (app.outdir / 'index.html').read_text(encoding='utf8')
 
-    if docutils.__version_info__ < (0, 17):
-        pattern = ('<div class="figure align-default" id="id1">\n'
-                   '<div class="graphviz">'
-                   '<object data="_images/inheritance-\\w+.svg" '
-                   'type="image/svg\\+xml" class="inheritance graphviz">\n'
-                   '<p class=\"warning\">Inheritance diagram of test.Foo</p>'
-                   '</object></div>\n<p class="caption"><span class="caption-text">'
-                   'Test Foo!</span><a class="headerlink" href="#id1" '
-                   'title="Permalink to this image">\xb6</a></p>\n</div>\n')
-    else:
-        pattern = ('<figure class="align-default" id="id1">\n'
-                   '<div class="graphviz">'
-                   '<object data="_images/inheritance-\\w+.svg" '
-                   'type="image/svg\\+xml" class="inheritance graphviz">\n'
-                   '<p class=\"warning\">Inheritance diagram of test.Foo</p>'
-                   '</object></div>\n<figcaption>\n<p><span class="caption-text">'
-                   'Test Foo!</span><a class="headerlink" href="#id1" '
-                   'title="Permalink to this image">\xb6</a></p>\n</figcaption>\n</figure>\n')
+    pattern = ('<figure class="align-default" id="id1">\n'
+               '<div class="graphviz">'
+               '<object data="_images/inheritance-\\w+.svg" '
+               'type="image/svg\\+xml" class="inheritance graphviz">\n'
+               '<p class=\"warning\">Inheritance diagram of test.Foo</p>'
+               '</object></div>\n<figcaption>\n<p><span class="caption-text">'
+               'Test Foo!</span><a class="headerlink" href="#id1" '
+               'title="Permalink to this image">\xb6</a></p>\n</figcaption>\n</figure>\n')
 
     assert re.search(pattern, content, re.M)
 
@@ -216,20 +197,12 @@ def test_inheritance_diagram_latex_alias(app, status, warning):
 
     content = (app.outdir / 'index.html').read_text(encoding='utf8')
 
-    if docutils.__version_info__ < (0, 17):
-        pattern = ('<div class="figure align-default" id="id1">\n'
-                   '<div class="graphviz">'
-                   '<img src="_images/inheritance-\\w+.png" alt="Inheritance diagram of test.Foo" '
-                   'class="inheritance graphviz" /></div>\n<p class="caption">'
-                   '<span class="caption-text">Test Foo!</span><a class="headerlink" href="#id1" '
-                   'title="Permalink to this image">\xb6</a></p>\n</div>\n')
-    else:
-        pattern = ('<figure class="align-default" id="id1">\n'
-                   '<div class="graphviz">'
-                   '<img src="_images/inheritance-\\w+.png" alt="Inheritance diagram of test.Foo" '
-                   'class="inheritance graphviz" /></div>\n<figcaption>\n<p>'
-                   '<span class="caption-text">Test Foo!</span><a class="headerlink" href="#id1" '
-                   'title="Permalink to this image">\xb6</a></p>\n</figcaption>\n</figure>\n')
+    pattern = ('<figure class="align-default" id="id1">\n'
+               '<div class="graphviz">'
+               '<img src="_images/inheritance-\\w+.png" alt="Inheritance diagram of test.Foo" '
+               'class="inheritance graphviz" /></div>\n<figcaption>\n<p>'
+               '<span class="caption-text">Test Foo!</span><a class="headerlink" href="#id1" '
+               'title="Permalink to this image">\xb6</a></p>\n</figcaption>\n</figure>\n')
     assert re.search(pattern, content, re.M)
 
 
diff --git a/tests/test_intl.py b/tests/test_intl.py
index 796d95bcc1e..9febfe0da26 100644
--- a/tests/test_intl.py
+++ b/tests/test_intl.py
@@ -6,7 +6,6 @@
 import os
 import re
 
-import docutils
 import pytest
 from babel.messages import mofile, pofile
 from babel.messages.catalog import Catalog
@@ -1121,12 +1120,8 @@ def test_additional_targets_should_not_be_translated(app):
     result = (app.outdir / 'raw.html').read_text(encoding='utf8')
 
     # raw block should not be translated
-    if docutils.__version_info__ < (0, 17):
-        expected_expr = """<iframe src="http://sphinx-doc.org"></iframe></div>"""
-        assert_count(expected_expr, result, 1)
-    else:
-        expected_expr = """<iframe src="http://sphinx-doc.org"></iframe></section>"""
-        assert_count(expected_expr, result, 1)
+    expected_expr = """<iframe src="http://sphinx-doc.org"></iframe></section>"""
+    assert_count(expected_expr, result, 1)
 
     # [figure.txt]
 
@@ -1203,12 +1198,8 @@ def test_additional_targets_should_be_translated(app):
     result = (app.outdir / 'raw.html').read_text(encoding='utf8')
 
     # raw block should be translated
-    if docutils.__version_info__ < (0, 17):
-        expected_expr = """<iframe src="HTTP://SPHINX-DOC.ORG"></iframe></div>"""
-        assert_count(expected_expr, result, 1)
-    else:
-        expected_expr = """<iframe src="HTTP://SPHINX-DOC.ORG"></iframe></section>"""
-        assert_count(expected_expr, result, 1)
+    expected_expr = """<iframe src="HTTP://SPHINX-DOC.ORG"></iframe></section>"""
+    assert_count(expected_expr, result, 1)
 
     # [figure.txt]
 
diff --git a/tests/test_markup.py b/tests/test_markup.py
index f15761c5e5d..4978a501dce 100644
--- a/tests/test_markup.py
+++ b/tests/test_markup.py
@@ -3,7 +3,6 @@
 import re
 import warnings
 
-import docutils
 import pytest
 from docutils import frontend, nodes, utils
 from docutils.parsers.rst import Parser as RstParser
@@ -395,8 +394,6 @@ def test_inline(get_verifier, type, rst, html_expected, latex_expected):
         None,
     ),
 ])
-@pytest.mark.skipif(docutils.__version_info__ < (0, 16),
-                    reason='docutils-0.16 or above is required')
 def test_inline_docutils16(get_verifier, type, rst, html_expected, latex_expected):
     verifier = get_verifier(type)
     verifier(rst, html_expected, latex_expected)
diff --git a/tox.ini b/tox.ini
index efbff445bbe..bdd3cef7626 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 minversion = 2.4.0
-envlist = docs,flake8,mypy,twine,py{38,39,310},du{14,15,16,17,18,19}
+envlist = docs,flake8,mypy,twine,py{38,39,310},du{17,18,19}
 isolated_build = True
 
 [testenv]
@@ -17,11 +17,8 @@ passenv =
     TERM
 description =
     py{38,39,310}: Run unit tests against {envname}.
-    du{14,15,16,17,18,19}: Run unit tests with the given version of docutils.
+    du{17,18,19}: Run unit tests with the given version of docutils.
 deps =
-    du14: docutils==0.14.*
-    du15: docutils==0.15.*
-    du16: docutils==0.16.*
     du17: docutils==0.17.*
     du18: docutils==0.18.*
     du19: docutils==0.19.*