Add 'noindex' meta robots tag to the search results page (#11700)

CHANGES.rst

@@ -34,6 +34,8 @@ Bugs fixed
 * #11483: singlehtml builder: Fix MathJax lazy loading when the index does not
   contain any math equations.
   Patch by Bénédikt Tran.
+* #11697: HTML Search: add 'noindex' meta robots tag.
+  Patch by James Addison.
 
 Testing
 -------

sphinx/themes/basic/search.html

@@ -15,8 +15,9 @@
     <script src="{{ pathto('_static/language_data.js', 1) }}"></script>
 {%- endblock %}
 {% block extrahead %}
-  <script src="{{ pathto('searchindex.js', 1) }}" defer></script>
-  {{ super() }}
+    <script src="{{ pathto('searchindex.js', 1) }}" defer></script>
+    <meta name="robots" content="noindex" />
+    {{ super() }}
 {% endblock %}
 {% block body %}
   <h1 id="search-documentation">{{ _('Search') }}</h1>

tests/test_build_html.py

@@ -399,6 +399,9 @@ def test_html4_error(make_app, tmp_path):
         (".//h1", "Generated section"),
         (".//a[@href='_sources/otherext.foo.txt']", ''),
     ],
+    'search.html': [
+        (".//meta[@name='robots'][@content='noindex']", ''),
+    ],
 }))
 @pytest.mark.sphinx('html', tags=['testtag'],
                     confoverrides={'html_context.hckey_co': 'hcval_co'})