Fix/9093 theme basic css import

AUTHORS.rst

@@ -97,6 +97,7 @@ Contributors
 * Matthew Woodcraft -- text output improvements
 * Matthias Geier -- style improvements
 * Michael Droettboom -- inheritance_diagram extension
+* Michael Hughes -- Merge inherited stylesheets in HTML themes
 * Michael Wilson -- Intersphinx HTTP basic auth support
 * Nathan Damon -- bugfix in validation of static paths in html builders
 * Nils Kattenbeck -- pygments dark style

CHANGES.rst

@@ -47,3 +47,5 @@ Bugs fixed
 * LaTeX: Fix accidental removal at ``3.5.0`` (#8854) of the documentation of
   ``literalblockcappos`` key of  :ref:`'sphinxsetup' <latexsphinxsetup>`.
   Patch by Jean-François B.
+* #9093: Merge inherited stylesheets in HTML themes instead of overwriting.
+  Patch by Michael Hughes

sphinx/ext/autosummary/generate.py

@@ -873,19 +873,23 @@ def find_autosummary_in_lines(
 def get_parser() -> argparse.ArgumentParser:
     parser = argparse.ArgumentParser(
         usage='%(prog)s [OPTIONS] <SOURCE_FILE>...',
-        epilog=__('For more information, visit <https://www.sphinx-doc.org/>.'),
-        description=__("""
-Generate ReStructuredText using autosummary directives.
+        epilog=str(__('For more information, visit <https://www.sphinx-doc.org/>.')),
+        description=str(
+            __(
+                """
+ Generate ReStructuredText using autosummary directives.
 
-sphinx-autogen is a frontend to sphinx.ext.autosummary.generate. It generates
-the reStructuredText files from the autosummary directives contained in the
-given input files.
+ sphinx-autogen is a frontend to sphinx.ext.autosummary.generate. It generates
+ the reStructuredText files from the autosummary directives contained in the
+ given input files.
 
-The format of the autosummary directive is documented in the
-``sphinx.ext.autosummary`` Python module and can be read using::
+ The format of the autosummary directive is documented in the
+ ``sphinx.ext.autosummary`` Python module and can be read using::
 
-  pydoc sphinx.ext.autosummary
-"""),
+   pydoc sphinx.ext.autosummary
+ """
+            )
+        ),
     )
 
     parser.add_argument(
@@ -896,58 +900,62 @@ def get_parser() -> argparse.ArgumentParser:
     )
 
     parser.add_argument(
-        'source_file', nargs='+', help=__('source files to generate rST files for')
+        'source_file',
+        nargs='+',
+        help=__('source files to generate rST files for'),
     )
 
     parser.add_argument(
         '-o',
         '--output-dir',
         action='store',
         dest='output_dir',
-        help=__('directory to place all output in'),
+        help=str(__('directory to place all output in')),
     )
     parser.add_argument(
         '-s',
         '--suffix',
         action='store',
         dest='suffix',
         default='rst',
-        help=__('default suffix for files (default: %(default)s)'),
+        help=str(__('default suffix for files (default: %(default)s)')),
     )
     parser.add_argument(
         '-t',
         '--templates',
         action='store',
         dest='templates',
         default=None,
-        help=__('custom template directory (default: %(default)s)'),
+        help=str(__('custom template directory (default: %(default)s)')),
     )
     parser.add_argument(
         '-i',
         '--imported-members',
         action='store_true',
         dest='imported_members',
         default=False,
-        help=__('document imported members (default: %(default)s)'),
+        help=str(__('document imported members (default: %(default)s)')),
     )
     parser.add_argument(
         '-a',
         '--respect-module-all',
         action='store_true',
         dest='respect_module_all',
         default=False,
-        help=__(
-            'document exactly the members in module __all__ attribute. '
-            '(default: %(default)s)'
+        help=str(
+            __(
+                'document exactly the members in module __all__ attribute. '
+                '(default: %(default)s)'
+            )
         ),
     )
     parser.add_argument(
         '--remove-old',
         action='store_true',
         dest='remove_old',
         default=False,
-        help=__(
-            'Remove existing files in the output directory that were not generated'
+        help=str(
+            __('Remove existing files in the output directory that were not generated')
         ),
     )
 

sphinx/theming.py

@@ -80,8 +80,12 @@ def __init__(
         self.pygments_style_dark: str | None = None
         for config in reversed(configs.values()):
             options |= config.options
-            if config.stylesheets is not None:
-                self.stylesheets = config.stylesheets
+            for stylesheet in config.stylesheets or ():
+                # Force conversion to string to resolve TranslationProxies
+                # and avoid TypeErrors during membership checks.
+                stylesheet_str = str(stylesheet)
+                if stylesheet_str not in self.stylesheets:
+                    self.stylesheets += (stylesheet_str,)
             if config.sidebar_templates is not None:
                 self.sidebar_templates = config.sidebar_templates
             if config.pygments_style_default is not None:

tests/test_builders/test_build_html_numfig.py

@@ -21,7 +21,7 @@
 @pytest.mark.sphinx('html', testroot='numfig')
 @pytest.mark.test_params(shared_result='test_build_html_numfig')
 def test_numfig_disabled_warn(app: SphinxTestApp) -> None:
-    app.build()
+    app.build(force_all=True)
     warnings = app.warning.getvalue()
     assert 'index.rst:47: WARNING: numfig is disabled. :numref: is ignored.' in warnings
     assert 'index.rst:56: WARNING: invalid numfig_format: invalid' not in warnings

tests/test_theming/test_theming.py

@@ -75,7 +75,7 @@ def test_theme_api(app: SphinxTestApp) -> None:
     assert len(theme.get_theme_dirs()) == 2
 
     # direct setting
-    assert theme.get_config('theme', 'stylesheet') == 'custom.css'
+    assert theme.get_config('theme', 'stylesheet') == 'basic.css, custom.css'
     # inherited setting
     assert theme.get_config('options', 'nosidebar') == 'false'
     # nonexisting setting
@@ -169,6 +169,7 @@ def test_dark_style(app: SphinxTestApp, monkeypatch: pytest.MonkeyPatch) -> None
     assert css_file.attributes['media'] == '(prefers-color-scheme: dark)'
 
     assert sorted(str(f.filename) for f in app.builder._css_files) == [
+        '_static/basic.css',
         '_static/classic.css',
         '_static/pygments.css',
         '_static/pygments_dark.css',