Merge branch '4.x'

28 files changed, 467 insertions, 152 deletions

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index f49117e1a..f32468576 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -21,7 +21,7 @@ jobs:
           docutils: du16
         - name: py39
           python: 3.9
-          docutils: du16
+          docutils: du17
           coverage: "--cov ./ --cov-append --cov-config setup.cfg"
         # - name: py310-dev
         #   python: 3.10-dev
diff --git a/CHANGES b/CHANGES
index 9e30c2497..c2522c6df 100644
--- a/CHANGES
+++ b/CHANGES
@@ -31,20 +31,34 @@ Incompatible changes
 Deprecated
 ----------
 
+* ``sphinx.util.docstrings.extract_metadata()``
+
 Features added
 --------------
 
+* #8107: autodoc: Add ``class-doc-from`` option to :rst:dir:`autoclass`
+  directive to control the content of the specific class like
+  :confval:`autoclass_content`
+* #8588: autodoc: :confval:`autodoc_type_aliases` now supports dotted name. It
+  allows you to define an alias for a class with module name like
+  ``foo.bar.BazClass``
 * #9129: html search: Show search summaries when html_copy_source = False
+* #9120: html theme: Eliminate prompt characters of code-block from copyable
+  text
 * #9097: Optimize the paralell build
 
 
 Bugs fixed
 ----------
 
+* #8872: autodoc: stacked singledispatches are wrongly rendered
+* #8597: autodoc: a docsting having metadata only should be treated as
+  undocumented
+
 Testing
 --------
 
-Release 4.0.0 beta2 (in development)
+Release 4.0.0 beta3 (in development)
 ====================================
 
 Dependencies
@@ -53,15 +67,37 @@ Dependencies
 Incompatible changes
 --------------------
 
-* #9023: Change the CSS classes on :rst:role:`cpp:expr` and
-  :rst:role:`cpp:texpr`.
-
 Deprecated
 ----------
 
 Features added
 --------------
 
+Bugs fixed
+----------
+
+Testing
+--------
+
+Release 4.0.0 beta2 (released Apr 29, 2021)
+===========================================
+
+Dependencies
+------------
+
+* Support docutils-0.17.  Please notice it changes the output of HTML builder.
+  Some themes do not support it, and you need to update your custom CSS to
+  upgrade it.
+
+Incompatible changes
+--------------------
+
+* #9023: Change the CSS classes on :rst:role:`cpp:expr` and
+  :rst:role:`cpp:texpr`.
+
+Features added
+--------------
+
 * #8818: autodoc: Super class having ``Any`` arguments causes nit-picky warning
 * #9095: autodoc: TypeError is raised on processing broken metaclass
 * #9110: autodoc: metadata of GenericAlias is not rendered as a reference in
@@ -81,9 +117,6 @@ Bugs fixed
 * C, C++, fix ``KeyError`` when an ``alias`` directive is the first C/C++
   directive in a file with another C/C++ directive later.
 
-Testing
---------
-
 Release 4.0.0 beta1 (released Apr 12, 2021)
 ===========================================
 
@@ -222,24 +255,6 @@ Bugs fixed
 Release 3.5.5 (in development)
 ==============================
 
-Dependencies
-------------
-
-Incompatible changes
---------------------
-
-Deprecated
-----------
-
-Features added
---------------
-
-Bugs fixed
-----------
-
-Testing
---------
-
 Release 3.5.4 (released Apr 11, 2021)
 =====================================
 
diff --git a/EXAMPLES b/EXAMPLES
index 040637e96..598f41b4f 100644
--- a/EXAMPLES
+++ b/EXAMPLES
@@ -12,7 +12,6 @@ interesting examples.
 Documentation using the alabaster theme
 ---------------------------------------
 
-* `AIOHTTP <https://docs.aiohttp.org/>`__
 * `Alabaster <https://alabaster.readthedocs.io/>`__
 * `Blinker <https://pythonhosted.org/blinker/>`__
 * `Calibre <https://manual.calibre-ebook.com/>`__
@@ -311,6 +310,7 @@ Documentation using sphinx_bootstrap_theme
 Documentation using a custom theme or integrated in a website
 -------------------------------------------------------------
 
+* `AIOHTTP <https://docs.aiohttp.org/>`__
 * `Apache Cassandra <https://cassandra.apache.org/doc/>`__
 * `Astropy <http://docs.astropy.org/>`__
 * `Bokeh <https://bokeh.pydata.org/>`__
diff --git a/doc/extdev/deprecated.rst b/doc/extdev/deprecated.rst
index 9e17b9fb4..514a80541 100644
--- a/doc/extdev/deprecated.rst
+++ b/doc/extdev/deprecated.rst
@@ -22,6 +22,11 @@ The following is a list of deprecated interfaces.
      - (will be) Removed
      - Alternatives
 
+   * - ``sphinx.util.docstrings.extract_metadata()``
+     - 4.1
+     - 6.0
+     - ``sphinx.util.docstrings.separate_metadata()``
+
    * - ``favicon`` variable in HTML templates
      - 4.0
      - TBD
diff --git a/doc/usage/extensions/autodoc.rst b/doc/usage/extensions/autodoc.rst
index da0ff7c99..13a2b3010 100644
--- a/doc/usage/extensions/autodoc.rst
+++ b/doc/usage/extensions/autodoc.rst
@@ -343,6 +343,10 @@ inserting them into the page source under a suitable :rst:dir:`py:module`,
 
         .. autoclass:: module.name::Noodle
 
+   * :rst:dir:`autoclass` also recognizes the ``class-doc-from`` option that
+     can be used to override the global value of :confval:`autoclass_content`.
+
+     .. versionadded:: 4.1
 
 .. rst:directive:: autofunction
                    autodecorator
@@ -507,7 +511,7 @@ There are also config values that you can set:
    The supported options are ``'members'``, ``'member-order'``,
    ``'undoc-members'``, ``'private-members'``, ``'special-members'``,
    ``'inherited-members'``, ``'show-inheritance'``, ``'ignore-module-all'``,
-   ``'imported-members'`` and ``'exclude-members'``.
+   ``'imported-members'``, ``'exclude-members'`` and ``'class-doc-from'``.
 
    .. versionadded:: 1.8
 
@@ -517,6 +521,9 @@ There are also config values that you can set:
    .. versionchanged:: 2.1
       Added ``'imported-members'``.
 
+   .. versionchanged:: 4.1
+      Added ``'class-doc-from'``.
+
 .. confval:: autodoc_docstring_signature
 
    Functions imported from C modules cannot be introspected, and therefore the
diff --git a/doc/usage/restructuredtext/domains.rst b/doc/usage/restructuredtext/domains.rst
index 65a32b6c8..dfd347327 100644
--- a/doc/usage/restructuredtext/domains.rst
+++ b/doc/usage/restructuredtext/domains.rst
@@ -1680,6 +1680,9 @@ There is a set of directives allowing documenting command-line programs:
    then ``:option:`rm -r``` would refer to the first option, while
    ``:option:`svn -r``` would refer to the second one.
 
+   If ``None`` is passed to the argument, the directive will reset the
+   current program name.
+
    The program name may contain spaces (in case you want to document
    subcommands like ``svn add`` and ``svn commit`` separately).
 
diff --git a/setup.py b/setup.py
index 1c14ff1eb..7ce37f9ea 100644
--- a/setup.py
+++ b/setup.py
@@ -21,9 +21,10 @@ install_requires = [
     'sphinxcontrib-htmlhelp',
     'sphinxcontrib-serializinghtml',
     'sphinxcontrib-qthelp',
-    'Jinja2>=2.3',
+    'Jinja2>=2.3,<3.0',
+    'MarkupSafe<2.0',
     'Pygments>=2.0',
-    'docutils>=0.14,<0.17',
+    'docutils>=0.14,<0.18',
     'snowballstemmer>=1.1',
     'babel>=1.3',
     'alabaster>=0.7,<0.8',
diff --git a/sphinx/builders/html/__init__.py b/sphinx/builders/html/__init__.py
index a78d54a16..87b9c5c45 100644
--- a/sphinx/builders/html/__init__.py
+++ b/sphinx/builders/html/__init__.py
@@ -1166,7 +1166,11 @@ def setup_js_tag_helper(app: Sphinx, pagename: str, templatename: str,
         else:
             # str value (old styled)
             attrs.append('src="%s"' % pathto(js, resource=True))
-        return '<script %s>%s</script>' % (' '.join(attrs), body)
+
+        if attrs:
+            return '<script %s>%s</script>' % (' '.join(attrs), body)
+        else:
+            return '<script>%s</script>' % body
 
     context['js_tag'] = js_tag
 
diff --git a/sphinx/builders/linkcheck.py b/sphinx/builders/linkcheck.py
index 05e12c173..a46b80c08 100644
--- a/sphinx/builders/linkcheck.py
+++ b/sphinx/builders/linkcheck.py
@@ -129,7 +129,7 @@ class CheckExternalLinksBuilder(DummyBuilder):
 
         # create queues and worker threads
         self._wqueue: PriorityQueue[CheckRequestType] = PriorityQueue()
-        self._rqueue: Queue = Queue()
+        self._rqueue: Queue[CheckResult] = Queue()
 
     @property
     def anchors_ignore(self) -> List[Pattern]:
@@ -228,43 +228,39 @@ class CheckExternalLinksBuilder(DummyBuilder):
         )
         return self._wqueue
 
-    def process_result(self, result: Tuple[str, str, int, str, str, int]) -> None:
-        uri, docname, lineno, status, info, code = result
+    def process_result(self, result: CheckResult) -> None:
+        filename = self.env.doc2path(result.docname, None)
 
-        filename = self.env.doc2path(docname, None)
-        linkstat = dict(filename=filename, lineno=lineno,
-                        status=status, code=code, uri=uri,
-                        info=info)
-        if status == 'unchecked':
-            self.write_linkstat(linkstat)
+        linkstat = dict(filename=filename, lineno=result.lineno,
+                        status=result.status, code=result.code, uri=result.uri,
+                        info=result.message)
+        self.write_linkstat(linkstat)
+
+        if result.status == 'unchecked':
             return
-        if status == 'working' and info == 'old':
-            self.write_linkstat(linkstat)
+        if result.status == 'working' and result.message == 'old':
             return
-        if lineno:
-            logger.info('(%16s: line %4d) ', docname, lineno, nonl=True)
-        if status == 'ignored':
-            if info:
-                logger.info(darkgray('-ignored- ') + uri + ': ' + info)
+        if result.lineno:
+            logger.info('(%16s: line %4d) ', result.docname, result.lineno, nonl=True)
+        if result.status == 'ignored':
+            if result.message:
+                logger.info(darkgray('-ignored- ') + result.uri + ': ' + result.message)
             else:
-                logger.info(darkgray('-ignored- ') + uri)
-            self.write_linkstat(linkstat)
-        elif status == 'local':
-            logger.info(darkgray('-local-   ') + uri)
-            self.write_entry('local', docname, filename, lineno, uri)
-            self.write_linkstat(linkstat)
-        elif status == 'working':
-            logger.info(darkgreen('ok        ') + uri + info)
-            self.write_linkstat(linkstat)
-        elif status == 'broken':
+                logger.info(darkgray('-ignored- ') + result.uri)
+        elif result.status == 'local':
+            logger.info(darkgray('-local-   ') + result.uri)
+            self.write_entry('local', result.docname, filename, result.lineno, result.uri)
+        elif result.status == 'working':
+            logger.info(darkgreen('ok        ') + result.uri + result.message)
+        elif result.status == 'broken':
             if self.app.quiet or self.app.warningiserror:
-                logger.warning(__('broken link: %s (%s)'), uri, info,
-                               location=(filename, lineno))
+                logger.warning(__('broken link: %s (%s)'), result.uri, result.message,
+                               location=(filename, result.lineno))
             else:
-                logger.info(red('broken    ') + uri + red(' - ' + info))
-            self.write_entry('broken', docname, filename, lineno, uri + ': ' + info)
-            self.write_linkstat(linkstat)
-        elif status == 'redirected':
+                logger.info(red('broken    ') + result.uri + red(' - ' + result.message))
+            self.write_entry('broken', result.docname, filename, result.lineno,
+                             result.uri + ': ' + result.message)
+        elif result.status == 'redirected':
             try:
                 text, color = {
                     301: ('permanently', purple),
@@ -272,16 +268,16 @@ class CheckExternalLinksBuilder(DummyBuilder):
                     303: ('with See Other', purple),
                     307: ('temporarily', turquoise),
                     308: ('permanently', purple),
-                }[code]
+                }[result.code]
             except KeyError:
                 text, color = ('with unknown code', purple)
             linkstat['text'] = text
-            logger.info(color('redirect  ') + uri + color(' - ' + text + ' to ' + info))
-            self.write_entry('redirected ' + text, docname, filename,
-                             lineno, uri + ' to ' + info)
-            self.write_linkstat(linkstat)
+            logger.info(color('redirect  ') + result.uri +
+                        color(' - ' + text + ' to ' + result.message))
+            self.write_entry('redirected ' + text, result.docname, filename,
+                             result.lineno, result.uri + ' to ' + result.message)
         else:
-            raise ValueError("Unknown status %s." % status)
+            raise ValueError("Unknown status %s." % result.status)
 
     def write_entry(self, what: str, docname: str, filename: str, line: int,
                     uri: str) -> None:
@@ -576,7 +572,7 @@ class HyperlinkAvailabilityCheckWorker(Thread):
             if status == 'rate-limited':
                 logger.info(darkgray('-rate limited-   ') + uri + darkgray(' | sleeping...'))
             else:
-                self.rqueue.put((uri, docname, lineno, status, info, code))
+                self.rqueue.put(CheckResult(uri, docname, lineno, status, info, code))
             self.wqueue.task_done()
 
     def limit_rate(self, response: Response) -> Optional[float]:
diff --git a/sphinx/ext/autodoc/__init__.py b/sphinx/ext/autodoc/__init__.py
index c92709deb..ff6475c94 100644
--- a/sphinx/ext/autodoc/__init__.py
+++ b/sphinx/ext/autodoc/__init__.py
@@ -30,7 +30,7 @@ from sphinx.ext.autodoc.mock import ismock, mock, undecorate
 from sphinx.locale import _, __
 from sphinx.pycode import ModuleAnalyzer, PycodeError
 from sphinx.util import inspect, logging
-from sphinx.util.docstrings import extract_metadata, prepare_docstring
+from sphinx.util.docstrings import prepare_docstring, separate_metadata
 from sphinx.util.inspect import (evaluate_signature, getdoc, object_description, safe_getattr,
                                  stringify_signature)
 from sphinx.util.typing import OptionSpec, get_type_hints, restify
@@ -129,6 +129,14 @@ def member_order_option(arg: Any) -> Optional[str]:
         raise ValueError(__('invalid value for member-order option: %s') % arg)
 
 
+def class_doc_from_option(arg: Any) -> Optional[str]:
+    """Used to convert the :class-doc-from: option to autoclass directives."""
+    if arg in ('both', 'class', 'init'):
+        return arg
+    else:
+        raise ValueError(__('invalid value for class-doc-from option: %s') % arg)
+
+
 SUPPRESS = object()
 
 
@@ -722,9 +730,9 @@ class Documenter:
                 # hack for ClassDocumenter to inject docstring via ObjectMember
                 doc = obj.docstring
 
+            doc, metadata = separate_metadata(doc)
             has_doc = bool(doc)
 
-            metadata = extract_metadata(doc)
             if 'private' in metadata:
                 # consider a member private if docstring has "private" metadata
                 isprivate = True
@@ -1320,12 +1328,12 @@ class FunctionDocumenter(DocstringSignatureMixin, ModuleLevelDocumenter):  # typ
                 if typ is object:
                     pass  # default implementation. skipped.
                 else:
-                    self.annotate_to_first_argument(func, typ)
-
-                    documenter = FunctionDocumenter(self.directive, '')
-                    documenter.object = func
-                    documenter.objpath = [None]
-                    sigs.append(documenter.format_signature())
+                    dispatchfunc = self.annotate_to_first_argument(func, typ)
+                    if dispatchfunc:
+                        documenter = FunctionDocumenter(self.directive, '')
+                        documenter.object = dispatchfunc
+                        documenter.objpath = [None]
+                        sigs.append(documenter.format_signature())
         if overloaded:
             actual = inspect.signature(self.object,
                                        type_aliases=self.config.autodoc_type_aliases)
@@ -1350,28 +1358,34 @@ class FunctionDocumenter(DocstringSignatureMixin, ModuleLevelDocumenter):  # typ
 
         return overload.replace(parameters=parameters)
 
-    def annotate_to_first_argument(self, func: Callable, typ: Type) -> None:
+    def annotate_to_first_argument(self, func: Callable, typ: Type) -> Optional[Callable]:
         """Annotate type hint to the first argument of function if needed."""
         try:
             sig = inspect.signature(func, type_aliases=self.config.autodoc_type_aliases)
         except TypeError as exc:
             logger.warning(__("Failed to get a function signature for %s: %s"),
                            self.fullname, exc)
-            return
+            return None
         except ValueError:
-            return
+            return None
 
         if len(sig.parameters) == 0:
-            return
+            return None
+
+        def dummy():
+            pass
 
         params = list(sig.parameters.values())
         if params[0].annotation is Parameter.empty:
             params[0] = params[0].replace(annotation=typ)
             try:
-                func.__signature__ = sig.replace(parameters=params)  # type: ignore
+                dummy.__signature__ = sig.replace(parameters=params)  # type: ignore
+                return dummy
             except (AttributeError, TypeError):
                 # failed to update signature (ex. built-in or extension types)
-                return
+                return None
+        else:
+            return None
 
 
 class DecoratorDocumenter(FunctionDocumenter):
@@ -1417,6 +1431,7 @@ class ClassDocumenter(DocstringSignatureMixin, ModuleLevelDocumenter):  # type:
         'show-inheritance': bool_option, 'member-order': member_order_option,
         'exclude-members': exclude_members_option,
         'private-members': members_option, 'special-members': members_option,
+        'class-doc-from': class_doc_from_option,
     }
 
     _signature_class: Any = None
@@ -1651,7 +1666,7 @@ class ClassDocumenter(DocstringSignatureMixin, ModuleLevelDocumenter):  # type:
         if lines is not None:
             return lines
 
-        content = self.config.autoclass_content
+        classdoc_from = self.options.get('class-doc-from', self.config.autoclass_content)
 
         docstrings = []
         attrdocstring = self.get_attr(self.object, '__doc__', None)
@@ -1660,7 +1675,7 @@ class ClassDocumenter(DocstringSignatureMixin, ModuleLevelDocumenter):  # type:
 
         # for classes, what the "docstring" is can be controlled via a
         # config value; the default is only the class docstring
-        if content in ('both', 'init'):
+        if classdoc_from in ('both', 'init'):
             __init__ = self.get_attr(self.object, '__init__', None)
             initdocstring = getdoc(__init__, self.get_attr,
                                    self.config.autodoc_inherit_docstrings,
@@ -1682,7 +1697,7 @@ class ClassDocumenter(DocstringSignatureMixin, ModuleLevelDocumenter):  # type:
                      initdocstring.strip() == object.__new__.__doc__)):  # for !pypy
                     initdocstring = None
             if initdocstring:
-                if content == 'init':
+                if classdoc_from == 'init':
                     docstrings = [initdocstring]
                 else:
                     docstrings.append(initdocstring)
@@ -1918,7 +1933,7 @@ class DataDocumenter(GenericAliasMixin, NewTypeMixin, TypeVarMixin,
             return True
         else:
             doc = self.get_doc()
-            metadata = extract_metadata('\n'.join(sum(doc, [])))
+            docstring, metadata = separate_metadata('\n'.join(sum(doc, [])))
             if 'hide-value' in metadata:
                 return True
 
@@ -2109,13 +2124,13 @@ class MethodDocumenter(DocstringSignatureMixin, ClassLevelDocumenter):  # type:
                 if typ is object:
                     pass  # default implementation. skipped.
                 else:
-                    self.annotate_to_first_argument(func, typ)
-
-                    documenter = MethodDocumenter(self.directive, '')
-                    documenter.parent = self.parent
-                    documenter.object = func
-                    documenter.objpath = [None]
-                    sigs.append(documenter.format_signature())
+                    dispatchmeth = self.annotate_to_first_argument(func, typ)
+                    if dispatchmeth:
+                        documenter = MethodDocumenter(self.directive, '')
+                        documenter.parent = self.parent
+                        documenter.object = dispatchmeth
+                        documenter.objpath = [None]
+                        sigs.append(documenter.format_signature())
         if overloaded:
             if inspect.isstaticmethod(self.object, cls=self.parent, name=self.object_name):
                 actual = inspect.signature(self.object, bound_method=False,
@@ -2149,27 +2164,34 @@ class MethodDocumenter(DocstringSignatureMixin, ClassLevelDocumenter):  # type:
 
         return overload.replace(parameters=parameters)
 
-    def annotate_to_first_argument(self, func: Callable, typ: Type) -> None:
+    def annotate_to_first_argument(self, func: Callable, typ: Type) -> Optional[Callable]:
         """Annotate type hint to the first argument of function if needed."""
         try:
             sig = inspect.signature(func, type_aliases=self.config.autodoc_type_aliases)
         except TypeError as exc:
             logger.warning(__("Failed to get a method signature for %s: %s"),
                            self.fullname, exc)
-            return
+            return None
         except ValueError:
-            return
+            return None
+
         if len(sig.parameters) == 1:
-            return
+            return None
+
+        def dummy():
+            pass
 
         params = list(sig.parameters.values())
         if params[1].annotation is Parameter.empty:
             params[1] = params[1].replace(annotation=typ)
             try:
-                func.__signature__ = sig.replace(parameters=params)  # type: ignore
+                dummy.__signature__ = sig.replace(parameters=params)  # type: ignore
+                return dummy
             except (AttributeError, TypeError):
                 # failed to update signature (ex. built-in or extension types)
-                return
+                return None
+        else:
+            return None
 
 
 class NonDataDescriptorMixin(DataDocumenterMixinBase):
@@ -2456,7 +2478,7 @@ class AttributeDocumenter(GenericAliasMixin, NewTypeMixin, SlotsMixin,  # type:
         else:
             doc = self.get_doc()
             if doc:
-                metadata = extract_metadata('\n'.join(sum(doc, [])))
+                docstring, metadata = separate_metadata('\n'.join(sum(doc, [])))
                 if 'hide-value' in metadata:
                     return True
 
diff --git a/sphinx/ext/autodoc/directive.py b/sphinx/ext/autodoc/directive.py
index c58d0c411..a554adf68 100644
--- a/sphinx/ext/autodoc/directive.py
+++ b/sphinx/ext/autodoc/directive.py
@@ -30,7 +30,7 @@ logger = logging.getLogger(__name__)
 AUTODOC_DEFAULT_OPTIONS = ['members', 'undoc-members', 'inherited-members',
                            'show-inheritance', 'private-members', 'special-members',
                            'ignore-module-all', 'exclude-members', 'member-order',
-                           'imported-members']
+                           'imported-members', 'class-doc-from']
 
 AUTODOC_EXTENDABLE_OPTIONS = ['members', 'private-members', 'special-members',
                               'exclude-members']
diff --git a/sphinx/themes/basic/static/basic.css_t b/sphinx/themes/basic/static/basic.css_t
index db43499ad..45815bac0 100644
--- a/sphinx/themes/basic/static/basic.css_t
+++ b/sphinx/themes/basic/static/basic.css_t
@@ -819,7 +819,7 @@ div.code-block-caption code {
 
 table.highlighttable td.linenos,
 span.linenos,
-div.doctest > div.highlight span.gp {  /* gp: Generic.Prompt */
+div.highlight span.gp {  /* gp: Generic.Prompt */
   user-select: none;
   -webkit-user-select: text; /* Safari fallback only */
   -webkit-user-select: none; /* Chrome/Safari */
diff --git a/sphinx/util/docstrings.py b/sphinx/util/docstrings.py
index 46bb5b9b8..d81d7dd99 100644
--- a/sphinx/util/docstrings.py
+++ b/sphinx/util/docstrings.py
@@ -11,26 +11,28 @@
 import re
 import sys
 import warnings
-from typing import Dict, List
+from typing import Dict, List, Tuple
 
 from docutils.parsers.rst.states import Body
 
-from sphinx.deprecation import RemovedInSphinx50Warning
+from sphinx.deprecation import RemovedInSphinx50Warning, RemovedInSphinx60Warning
 
 field_list_item_re = re.compile(Body.patterns['field_marker'])
 
 
-def extract_metadata(s: str) -> Dict[str, str]:
-    """Extract metadata from docstring."""
+def separate_metadata(s: str) -> Tuple[str, Dict[str, str]]:
+    """Separate docstring into metadata and others."""
     in_other_element = False
     metadata: Dict[str, str] = {}
+    lines = []
 
     if not s:
-        return metadata
+        return s, metadata
 
     for line in prepare_docstring(s):
         if line.strip() == '':
             in_other_element = False
+            lines.append(line)
         else:
             matched = field_list_item_re.match(line)
             if matched and not in_other_element:
@@ -38,9 +40,20 @@ def extract_metadata(s: str) -> Dict[str, str]:
                 if field_name.startswith('meta '):
                     name = field_name[5:].strip()
                     metadata[name] = line[matched.end():].strip()
+                else:
+                    lines.append(line)
             else:
                 in_other_element = True
+                lines.append(line)
+
+    return '\n'.join(lines), metadata
+
+
+def extract_metadata(s: str) -> Dict[str, str]:
+    warnings.warn("extract_metadata() is deprecated.",
+                  RemovedInSphinx60Warning, stacklevel=2)
 
+    docstring, metadata = separate_metadata(s)
     return metadata
 
 
diff --git a/sphinx/util/inspect.py b/sphinx/util/inspect.py
index 7c9adb0bf..f216e8797 100644
--- a/sphinx/util/inspect.py
+++ b/sphinx/util/inspect.py
@@ -18,8 +18,10 @@ import types
 import typing
 import warnings
 from functools import partial, partialmethod
+from importlib import import_module
 from inspect import Parameter, isclass, ismethod, ismethoddescriptor, ismodule  # NOQA
 from io import StringIO
+from types import ModuleType
 from typing import Any, Callable, Dict, Mapping, Optional, Sequence, Tuple, Type, cast
 
 from sphinx.deprecation import RemovedInSphinx50Warning
@@ -501,6 +503,78 @@ class DefaultValue:
         return self.value
 
 
+class TypeAliasForwardRef:
+    """Pseudo typing class for autodoc_type_aliases.
+
+    This avoids the error on evaluating the type inside `get_type_hints()`.
+    """
+    def __init__(self, name: str) -> None:
+        self.name = name
+
+    def __call__(self) -> None:
+        # Dummy method to imitate special typing classes
+        pass
+
+    def __eq__(self, other: Any) -> bool:
+        return self.name == other
+
+
+class TypeAliasModule:
+    """Pseudo module class for autodoc_type_aliases."""
+
+    def __init__(self, modname: str, mapping: Dict[str, str]) -> None:
+        self.__modname = modname
+        self.__mapping = mapping
+
+        self.__module: Optional[ModuleType] = None
+
+    def __getattr__(self, name: str) -> Any:
+        fullname = '.'.join(filter(None, [self.__modname, name]))
+        if fullname in self.__mapping:
+            # exactly matched
+            return TypeAliasForwardRef(self.__mapping[fullname])
+        else:
+            prefix = fullname + '.'
+            nested = {k: v for k, v in self.__mapping.items() if k.startswith(prefix)}
+            if nested:
+                # sub modules or classes found
+                return TypeAliasModule(fullname, nested)
+            else:
+                # no sub modules or classes found.
+                try:
+                    # return the real submodule if exists
+                    return import_module(fullname)
+                except ImportError:
+                    # return the real class
+                    if self.__module is None:
+                        self.__module = import_module(self.__modname)
+
+                    return getattr(self.__module, name)
+
+
+class TypeAliasNamespace(Dict[str, Any]):
+    """Pseudo namespace class for autodoc_type_aliases.
+
+    This enables to look up nested modules and classes like `mod1.mod2.Class`.
+    """
+
+    def __init__(self, mapping: Dict[str, str]) -> None:
+        self.__mapping = mapping
+
+    def __getitem__(self, key: str) -> Any:
+        if key in self.__mapping:
+            # exactly matched
+            return TypeAliasForwardRef(self.__mapping[key])
+        else:
+            prefix = key + '.'
+            nested = {k: v for k, v in self.__mapping.items() if k.startswith(prefix)}
+            if nested:
+                # sub modules or classes found
+                return TypeAliasModule(key, nested)
+            else:
+                raise KeyError
+
+
 def _should_unwrap(subject: Callable) -> bool:
     """Check the function should be unwrapped on getting signature."""
     __globals__ = getglobals(subject)
@@ -549,12 +623,19 @@ def signature(subject: Callable, bound_method: bool = False, follow_wrapped: boo
 
     try:
         # Resolve annotations using ``get_type_hints()`` and type_aliases.
-        annotations = typing.get_type_hints(subject, None, type_aliases)
+        localns = TypeAliasNamespace(type_aliases)
+        annotations = typing.get_type_hints(subject, None, localns)
         for i, param in enumerate(parameters):
             if param.name in annotations:
-                parameters[i] = param.replace(annotation=annotations[param.name])
+                annotation = annotations[param.name]
+                if isinstance(annotation, TypeAliasForwardRef):
+                    annotation = annotation.name
+                parameters[i] = param.replace(annotation=annotation)
         if 'return' in annotations:
-            return_annotation = annotations['return']
+            if isinstance(annotations['return'], TypeAliasForwardRef):
+                return_annotation = annotations['return'].name
+            else:
+                return_annotation = annotations['return']
     except Exception:
         # ``get_type_hints()`` does not support some kind of objects like partial,
         # ForwardRef and so on.
diff --git a/sphinx/util/texescape.py b/sphinx/util/texescape.py
index 417a963a7..8dcc08a9b 100644
--- a/sphinx/util/texescape.py
+++ b/sphinx/util/texescape.py
@@ -29,6 +29,8 @@ tex_replacements = [
     # map special Unicode characters to TeX commands
     ('✓', r'\(\checkmark\)'),
     ('✔', r'\(\pmb{\checkmark}\)'),
+    ('✕', r'\(\times\)'),
+    ('✖', r'\(\pmb{\times}\)'),
     # used to separate -- in options
     ('', r'{}'),
     # map some special Unicode characters to similar ASCII ones
diff --git a/tests/roots/test-ext-autodoc/target/annotations.py b/tests/roots/test-ext-autodoc/target/autodoc_type_aliases.py
index ef600e2af..d8a2fecef 100644
--- a/tests/roots/test-ext-autodoc/target/annotations.py
+++ b/tests/roots/test-ext-autodoc/target/autodoc_type_aliases.py
@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import io
 from typing import overload
 
 myint = int
@@ -11,6 +12,10 @@ variable: myint
 variable2 = None  # type: myint
 
 
+def read(r: io.BytesIO) -> io.StringIO:
+    """docstring"""
+
+
 def sum(x: myint, y: myint) -> myint:
     """docstring"""
     return x + y
diff --git a/tests/roots/test-ext-autodoc/target/metadata.py b/tests/roots/test-ext-autodoc/target/metadata.py
new file mode 100644
index 000000000..7a4488f67
--- /dev/null
+++ b/tests/roots/test-ext-autodoc/target/metadata.py
@@ -0,0 +1,2 @@
+def foo():
+    """:meta metadata-only-docstring:"""
diff --git a/tests/roots/test-ext-autodoc/target/singledispatch.py b/tests/roots/test-ext-autodoc/target/singledispatch.py
index 3fa81dcae..fca2b6683 100644
--- a/tests/roots/test-ext-autodoc/target/singledispatch.py
+++ b/tests/roots/test-ext-autodoc/target/singledispatch.py
@@ -15,6 +15,7 @@ def func(arg, kwarg=None):
 
 
 @func.register(int)
+@func.register(float)
 def _func_int(arg, kwarg=None):
     """A function for int."""
     pass
diff --git a/tests/roots/test-ext-autodoc/target/singledispatchmethod.py b/tests/roots/test-ext-autodoc/target/singledispatchmethod.py
index b5ccbb2f0..086c7fe66 100644
--- a/tests/roots/test-ext-autodoc/target/singledispatchmethod.py
+++ b/tests/roots/test-ext-autodoc/target/singledispatchmethod.py
@@ -10,6 +10,7 @@ class Foo:
         pass
 
     @meth.register(int)
+    @meth.register(float)
     def _meth_int(self, arg, kwarg=None):
         """A method for int."""
         pass
diff --git a/tests/roots/test-root/conf.py b/tests/roots/test-root/conf.py
index 34cafa767..687445a70 100644
--- a/tests/roots/test-root/conf.py
+++ b/tests/roots/test-root/conf.py
@@ -42,7 +42,7 @@ latex_additional_files = ['svgimg.svg']
 coverage_c_path = ['special/*.h']
 coverage_c_regexes = {'function': r'^PyAPI_FUNC\(.*\)\s+([^_][\w_]+)'}
 
-extlinks = {'issue': ('http://bugs.python.org/issue%s', 'issue '),
+extlinks = {'issue': ('http://bugs.python.org/issue%s', 'issue %s'),
             'pyurl': ('http://python.org/%s', None)}
 
 # modify tags from conf.py
diff --git a/tests/test_domain_std.py b/tests/test_domain_std.py
index 9d9e27bd0..011c82f6a 100644
--- a/tests/test_domain_std.py
+++ b/tests/test_domain_std.py
@@ -324,6 +324,23 @@ def test_cmdoption(app):
     assert domain.progoptions[('ls', '-l')] == ('index', 'cmdoption-ls-l')
 
 
+def test_cmdoption_for_None(app):
+    text = (".. program:: ls\n"
+            ".. program:: None\n"
+            "\n"
+            ".. option:: -l\n")
+    domain = app.env.get_domain('std')
+    doctree = restructuredtext.parse(app, text)
+    assert_node(doctree, (addnodes.index,
+                          [desc, ([desc_signature, ([desc_name, "-l"],
+                                                    [desc_addname, ()])],
+                                  [desc_content, ()])]))
+    assert_node(doctree[0], addnodes.index,
+                entries=[('pair', 'command line option; -l', 'cmdoption-l', '', None)])
+    assert (None, '-l') in domain.progoptions
+    assert domain.progoptions[(None, '-l')] == ('index', 'cmdoption-l')
+
+
 def test_multiple_cmdoptions(app):
     text = (".. program:: cmd\n"
             "\n"
diff --git a/tests/test_ext_autodoc.py b/tests/test_ext_autodoc.py
index 2becf5de2..4c16886b3 100644
--- a/tests/test_ext_autodoc.py
+++ b/tests/test_ext_autodoc.py
@@ -736,6 +736,34 @@ def test_autodoc_undoc_members(app):
 
 
 @pytest.mark.sphinx('html', testroot='ext-autodoc')
+def test_autodoc_undoc_members_for_metadata_only(app):
+    # metadata only member is not displayed
+    options = {"members": None}
+    actual = do_autodoc(app, 'module', 'target.metadata', options)
+    assert list(actual) == [
+        '',
+        '.. py:module:: target.metadata',
+        '',
+    ]
+
+    # metadata only member is displayed when undoc-member given
+    options = {"members": None,
+               "undoc-members": None}
+    actual = do_autodoc(app, 'module', 'target.metadata', options)
+    assert list(actual) == [
+        '',
+        '.. py:module:: target.metadata',
+        '',
+        '',
+        '.. py:function:: foo()',
+        '   :module: target.metadata',
+        '',
+        '   :meta metadata-only-docstring:',
+        '',
+    ]
+
+
+@pytest.mark.sphinx('html', testroot='ext-autodoc')
 def test_autodoc_inherited_members(app):
     options = {"members": None,
                "inherited-members": None}
@@ -2080,6 +2108,7 @@ def test_singledispatch(app):
         '',
         '',
         '.. py:function:: func(arg, kwarg=None)',
+        '                 func(arg: float, kwarg=None)',
         '                 func(arg: int, kwarg=None)',
         '                 func(arg: str, kwarg=None)',
         '   :module: target.singledispatch',
@@ -2107,6 +2136,7 @@ def test_singledispatchmethod(app):
         '',
         '',
         '   .. py:method:: Foo.meth(arg, kwarg=None)',
+        '                  Foo.meth(arg: float, kwarg=None)',
         '                  Foo.meth(arg: int, kwarg=None)',
         '                  Foo.meth(arg: str, kwarg=None)',
         '      :module: target.singledispatchmethod',
@@ -2125,6 +2155,7 @@ def test_singledispatchmethod_automethod(app):
     assert list(actual) == [
         '',
         '.. py:method:: Foo.meth(arg, kwarg=None)',
+        '               Foo.meth(arg: float, kwarg=None)',
         '               Foo.meth(arg: int, kwarg=None)',
         '               Foo.meth(arg: str, kwarg=None)',
         '   :module: target.singledispatchmethod',
diff --git a/tests/test_ext_autodoc_autoclass.py b/tests/test_ext_autodoc_autoclass.py
index d879f8e14..096dc9397 100644
--- a/tests/test_ext_autodoc_autoclass.py
+++ b/tests/test_ext_autodoc_autoclass.py
@@ -264,6 +264,53 @@ def test_show_inheritance_for_subclass_of_generic_type(app):
     ]
 
 
+@pytest.mark.sphinx('html', testroot='ext-autodoc')
+def test_class_doc_from_class(app):
+    options = {"members": None,
+               "class-doc-from": "class"}
+    actual = do_autodoc(app, 'class', 'target.autoclass_content.C', options)
+    assert list(actual) == [
+        '',
+        '.. py:class:: C()',
+        '   :module: target.autoclass_content',
+        '',
+        '   A class having __init__, no __new__',
+        '',
+    ]
+
+
+@pytest.mark.sphinx('html', testroot='ext-autodoc')
+def test_class_doc_from_init(app):
+    options = {"members": None,
+               "class-doc-from": "init"}
+    actual = do_autodoc(app, 'class', 'target.autoclass_content.C', options)
+    assert list(actual) == [
+        '',
+        '.. py:class:: C()',
+        '   :module: target.autoclass_content',
+        '',
+        '   __init__ docstring',
+        '',
+    ]
+
+
+@pytest.mark.sphinx('html', testroot='ext-autodoc')
+def test_class_doc_from_both(app):
+    options = {"members": None,
+               "class-doc-from": "both"}
+    actual = do_autodoc(app, 'class', 'target.autoclass_content.C', options)
+    assert list(actual) == [
+        '',
+        '.. py:class:: C()',
+        '   :module: target.autoclass_content',
+        '',
+        '   A class having __init__, no __new__',
+        '',
+        '   __init__ docstring',
+        '',
+    ]
+
+
 def test_class_alias(app):
     def autodoc_process_docstring(*args):
         """A handler always raises an error.
diff --git a/tests/test_ext_autodoc_autofunction.py b/tests/test_ext_autodoc_autofunction.py
index 615091889..ca2429b5e 100644
--- a/tests/test_ext_autodoc_autofunction.py
+++ b/tests/test_ext_autodoc_autofunction.py
@@ -119,6 +119,7 @@ def test_singledispatch(app):
     assert list(actual) == [
         '',
         '.. py:function:: func(arg, kwarg=None)',
+        '                 func(arg: float, kwarg=None)',
         '                 func(arg: int, kwarg=None)',
         '                 func(arg: str, kwarg=None)',
         '   :module: target.singledispatch',
diff --git a/tests/test_ext_autodoc_configs.py b/tests/test_ext_autodoc_configs.py
index bc8c01fbd..04d35e335 100644
--- a/tests/test_ext_autodoc_configs.py
+++ b/tests/test_ext_autodoc_configs.py
@@ -792,27 +792,27 @@ def test_autodoc_typehints_description_for_invalid_node(app):
 def test_autodoc_type_aliases(app):
     # default
     options = {"members": None}
-    actual = do_autodoc(app, 'module', 'target.annotations', options)
+    actual = do_autodoc(app, 'module', 'target.autodoc_type_aliases', options)
     assert list(actual) == [
         '',
-        '.. py:module:: target.annotations',
+        '.. py:module:: target.autodoc_type_aliases',
         '',
         '',
         '.. py:class:: Foo()',
-        '   :module: target.annotations',
+        '   :module: target.autodoc_type_aliases',
         '',
         '   docstring',
         '',
         '',
         '   .. py:attribute:: Foo.attr1',
-        '      :module: target.annotations',
+        '      :module: target.autodoc_type_aliases',
         '      :type: int',
         '',
         '      docstring',
         '',
         '',
         '   .. py:attribute:: Foo.attr2',
-        '      :module: target.annotations',
+        '      :module: target.autodoc_type_aliases',
         '      :type: int',
         '',
         '      docstring',
@@ -820,26 +820,32 @@ def test_autodoc_type_aliases(app):
         '',
         '.. py:function:: mult(x: int, y: int) -> int',
         '                 mult(x: float, y: float) -> float',
-        '   :module: target.annotations',
+        '   :module: target.autodoc_type_aliases',
+        '',
+        '   docstring',
+        '',
+        '',
+        '.. py:function:: read(r: _io.BytesIO) -> _io.StringIO',
+        '   :module: target.autodoc_type_aliases',
         '',
         '   docstring',
         '',
         '',
         '.. py:function:: sum(x: int, y: int) -> int',
-        '   :module: target.annotations',
+        '   :module: target.autodoc_type_aliases',
         '',
         '   docstring',
         '',
         '',
         '.. py:data:: variable',
-        '   :module: target.annotations',
+        '   :module: target.autodoc_type_aliases',
         '   :type: int',
         '',
         '   docstring',
         '',
         '',
         '.. py:data:: variable2',
-        '   :module: target.annotations',
+        '   :module: target.autodoc_type_aliases',
         '   :type: int',
         '   :value: None',
         '',
@@ -848,28 +854,29 @@ def test_autodoc_type_aliases(app):
     ]
 
     # define aliases
-    app.config.autodoc_type_aliases = {'myint': 'myint'}
-    actual = do_autodoc(app, 'module', 'target.annotations', options)
+    app.config.autodoc_type_aliases = {'myint': 'myint',
+                                       'io.StringIO': 'my.module.StringIO'}
+    actual = do_autodoc(app, 'module', 'target.autodoc_type_aliases', options)
     assert list(actual) == [
         '',
-        '.. py:module:: target.annotations',
+        '.. py:module:: target.autodoc_type_aliases',
         '',
         '',
         '.. py:class:: Foo()',
-        '   :module: target.annotations',
+        '   :module: target.autodoc_type_aliases',
         '',
         '   docstring',
         '',
         '',
         '   .. py:attribute:: Foo.attr1',
-        '      :module: target.annotations',
+        '      :module: target.autodoc_type_aliases',
         '      :type: myint',
         '',
         '      docstring',
         '',
         '',
         '   .. py:attribute:: Foo.attr2',
-        '      :module: target.annotations',
+        '      :module: target.autodoc_type_aliases',
         '      :type: myint',
         '',
         '      docstring',
@@ -877,26 +884,32 @@ def test_autodoc_type_aliases(app):
         '',
         '.. py:function:: mult(x: myint, y: myint) -> myint',
         '                 mult(x: float, y: float) -> float',
-        '   :module: target.annotations',
+        '   :module: target.autodoc_type_aliases',
+        '',
+        '   docstring',
+        '',
+        '',
+        '.. py:function:: read(r: _io.BytesIO) -> my.module.StringIO',
+        '   :module: target.autodoc_type_aliases',
         '',
         '   docstring',
         '',
         '',
         '.. py:function:: sum(x: myint, y: myint) -> myint',
-        '   :module: target.annotations',
+        '   :module: target.autodoc_type_aliases',
         '',
         '   docstring',
         '',
         '',
         '.. py:data:: variable',
-        '   :module: target.annotations',
+        '   :module: target.autodoc_type_aliases',
         '   :type: myint',
         '',
         '   docstring',
         '',
         '',
         '.. py:data:: variable2',
-        '   :module: target.annotations',
+        '   :module: target.autodoc_type_aliases',
         '   :type: myint',
         '   :value: None',
         '',
@@ -911,10 +924,10 @@ def test_autodoc_type_aliases(app):
                     confoverrides={'autodoc_typehints': "description",
                                    'autodoc_type_aliases': {'myint': 'myint'}})
 def test_autodoc_typehints_description_and_type_aliases(app):
-    (app.srcdir / 'annotations.rst').write_text('.. autofunction:: target.annotations.sum')
+    (app.srcdir / 'autodoc_type_aliases.rst').write_text('.. autofunction:: target.autodoc_type_aliases.sum')
     app.build()
-    context = (app.outdir / 'annotations.txt').read_text()
-    assert ('target.annotations.sum(x, y)\n'
+    context = (app.outdir / 'autodoc_type_aliases.txt').read_text()
+    assert ('target.autodoc_type_aliases.sum(x, y)\n'
             '\n'
             '   docstring\n'
             '\n'
diff --git a/tests/test_ext_math.py b/tests/test_ext_math.py
index bd124c8c6..ebe2c0f38 100644
--- a/tests/test_ext_math.py
+++ b/tests/test_ext_math.py
@@ -215,11 +215,23 @@ def test_math_compat(app, status, warning):
 
 @pytest.mark.sphinx('html', testroot='ext-math',
                     confoverrides={'extensions': ['sphinx.ext.mathjax'],
-                                   'mathjax_config': {'extensions': ['tex2jax.js']}})
-def test_mathjax_config(app, status, warning):
+                                   'mathjax3_config': {'extensions': ['tex2jax.js']}})
+def test_mathjax3_config(app, status, warning):
     app.builder.build_all()
 
     content = (app.outdir / 'index.html').read_text()
+    assert MATHJAX_URL in content
+    assert ('<script>window.MathJax = {"extensions": ["tex2jax.js"]}</script>' in content)
+
+
+@pytest.mark.sphinx('html', testroot='ext-math',
+                    confoverrides={'extensions': ['sphinx.ext.mathjax'],
+                                   'mathjax2_config': {'extensions': ['tex2jax.js']}})
+def test_mathjax2_config(app, status, warning):
+    app.builder.build_all()
+
+    content = (app.outdir / 'index.html').read_text()
+    assert MATHJAX_URL in content
     assert ('<script type="text/x-mathjax-config">'
             'MathJax.Hub.Config({"extensions": ["tex2jax.js"]})'
             '</script>' in content)
diff --git a/tests/test_util_docstrings.py b/tests/test_util_docstrings.py
index 543feca2a..2d406b81c 100644
--- a/tests/test_util_docstrings.py
+++ b/tests/test_util_docstrings.py
@@ -8,31 +8,48 @@
     :license: BSD, see LICENSE for details.
 """
 
-from sphinx.util.docstrings import extract_metadata, prepare_commentdoc, prepare_docstring
+from sphinx.util.docstrings import prepare_commentdoc, prepare_docstring, separate_metadata
 
 
-def test_extract_metadata():
-    metadata = extract_metadata(":meta foo: bar\n"
-                                ":meta baz:\n")
+def test_separate_metadata():
+    # metadata only
+    text = (":meta foo: bar\n"
+            ":meta baz:\n")
+    docstring, metadata = separate_metadata(text)
+    assert docstring == ''
     assert metadata == {'foo': 'bar', 'baz': ''}
 
+    # non metadata field list item
+    text = (":meta foo: bar\n"
+            ":param baz:\n")
+    docstring, metadata = separate_metadata(text)
+    assert docstring == ':param baz:\n'
+    assert metadata == {'foo': 'bar'}
+
     # field_list like text following just after paragaph is not a field_list
-    metadata = extract_metadata("blah blah blah\n"
-                                ":meta foo: bar\n"
-                                ":meta baz:\n")
+    text = ("blah blah blah\n"
+            ":meta foo: bar\n"
+            ":meta baz:\n")
+    docstring, metadata = separate_metadata(text)
+    assert docstring == text
     assert metadata == {}
 
     # field_list like text following after blank line is a field_list
-    metadata = extract_metadata("blah blah blah\n"
-                                "\n"
-                                ":meta foo: bar\n"
-                                ":meta baz:\n")
+    text = ("blah blah blah\n"
+            "\n"
+            ":meta foo: bar\n"
+            ":meta baz:\n")
+    docstring, metadata = separate_metadata(text)
+    assert docstring == "blah blah blah\n\n"
     assert metadata == {'foo': 'bar', 'baz': ''}
 
     # non field_list item breaks field_list
-    metadata = extract_metadata(":meta foo: bar\n"
-                                "blah blah blah\n"
-                                ":meta baz:\n")
+    text = (":meta foo: bar\n"
+            "blah blah blah\n"
+            ":meta baz:\n")
+    docstring, metadata = separate_metadata(text)
+    assert docstring == ("blah blah blah\n"
+                         ":meta baz:\n")
     assert metadata == {'foo': 'bar'}
 
 
diff --git a/tests/test_util_inspect.py b/tests/test_util_inspect.py
index 7b86c6ade..fbf243ba1 100644
--- a/tests/test_util_inspect.py
+++ b/tests/test_util_inspect.py
@@ -19,7 +19,26 @@ import _testcapi
 import pytest
 
 from sphinx.util import inspect
-from sphinx.util.inspect import stringify_signature
+from sphinx.util.inspect import TypeAliasNamespace, stringify_signature
+
+
+def test_TypeAliasNamespace():
+    import logging.config
+    type_alias = TypeAliasNamespace({'logging.Filter': 'MyFilter',
+                                     'logging.Handler': 'MyHandler',
+                                     'logging.handlers.SyslogHandler': 'MySyslogHandler'})
+
+    assert type_alias['logging'].Filter == 'MyFilter'
+    assert type_alias['logging'].Handler == 'MyHandler'
+    assert type_alias['logging'].handlers.SyslogHandler == 'MySyslogHandler'
+    assert type_alias['logging'].Logger == logging.Logger
+    assert type_alias['logging'].config == logging.config
+
+    with pytest.raises(KeyError):
+        assert type_alias['log']
+
+    with pytest.raises(KeyError):
+        assert type_alias['unknown']
 
 
 def test_signature():