Add intersphinx_disabled_domains

Fixes sphinx-doc/sphinx#2068
Replaces sphinx-doc/sphinx#8981

5 files changed, 127 insertions, 33 deletions

diff --git a/CHANGES b/CHANGES
index ffb1cdc47..06c8d7281 100644
--- a/CHANGES
+++ b/CHANGES
@@ -47,6 +47,11 @@ Features added
 * #9695: More CSS classes on Javascript domain descriptions
 * #9683: Revert the removal of ``add_stylesheet()`` API.  It will be kept until
   the Sphinx-6.0 release
+* #2068, add :confval:`intersphinx_disabled_domains` for disabling
+  interphinx resolution of cross-references in specific domains when they
+  do not have an explicit inventory specification.
+  ``sphinx-quickstart`` will insert
+  ``intersphinx_disabled_domains = ['std']`` in its generated ``conf.py``.
 
 Bugs fixed
 ----------
diff --git a/doc/usage/extensions/intersphinx.rst b/doc/usage/extensions/intersphinx.rst
index 478ddb7ae..5f4d1e7c9 100644
--- a/doc/usage/extensions/intersphinx.rst
+++ b/doc/usage/extensions/intersphinx.rst
@@ -148,6 +148,25 @@ linking:
       exception is raised if the server has not issued a response for timeout
       seconds.
 
+.. confval:: intersphinx_disabled_domains
+
+   .. versionadded:: 4.2
+
+   A list of strings being the name of a domain, or the special name ``all``.
+   When a cross-reference without an explicit inventory specification is being
+   resolve by intersphinx, skip resolution if either the domain of the
+   cross-reference is in this list or the special name ``all`` is in the list.
+
+   For example, with ``intersphinx_disabled_domains = ['std']`` a cross-reference
+   ``:doc:`installation``` will not be attempted to be resolved by intersphinx, but
+   ``:doc:`otherbook:installation``` will be attempted to be resolved in the
+   inventory named ``otherbook`` in :confval:`intersphinx_mapping`.
+   At the same time, all cross-references generated in, e.g., Python, declarations
+   will still be attempted to be resolved by intersphinx.
+
+   If ``all`` is in the list of domains, then no references without an explicit
+   inventory will be resolved by intersphinx.
+
 
 Showing all links of an Intersphinx mapping file
 ------------------------------------------------
diff --git a/sphinx/ext/intersphinx.py b/sphinx/ext/intersphinx.py
index 848a12eb4..7764390ee 100644
--- a/sphinx/ext/intersphinx.py
+++ b/sphinx/ext/intersphinx.py
@@ -351,11 +351,20 @@ def _resolve_reference_in_domain(inv_name: Optional[str], inventory: Inventory,
 
 
 def _resolve_reference(env: BuildEnvironment, inv_name: Optional[str], inventory: Inventory,
+                       honor_disabled_domains: bool,
                        node: pending_xref, contnode: TextElement) -> Optional[Element]:
-    # figure out which object types we should look for
+    # disabling should only be done if no inventory is given
+    honor_disabled_domains = honor_disabled_domains and inv_name is None
+
+    if honor_disabled_domains and 'all' in env.config.intersphinx_disabled_domains:
+        return None
+
     typ = node['reftype']
     if typ == 'any':
         for domain_name, domain in env.domains.items():
+            if honor_disabled_domains \
+                    and domain_name in env.config.intersphinx_disabled_domains:
+                continue
             objtypes = list(domain.object_types)
             res = _resolve_reference_in_domain(inv_name, inventory,
                                                domain, objtypes,
@@ -368,6 +377,9 @@ def _resolve_reference(env: BuildEnvironment, inv_name: Optional[str], inventory
         if not domain_name:
             # only objects in domains are in the inventory
             return None
+        if honor_disabled_domains \
+                and domain_name in env.config.intersphinx_disabled_domains:
+            return None
         domain = env.get_domain(domain_name)
         objtypes = domain.objtypes_for_role(typ)
         if not objtypes:
@@ -383,8 +395,8 @@ def inventory_exists(env: BuildEnvironment, inv_name: str) -> bool:
 
 def resolve_reference_in_inventory(env: BuildEnvironment,
                                    inv_name: str,
-                                   node: pending_xref,
-                                   contnode: TextElement) -> Optional[Element]:
+                                   node: pending_xref, contnode: TextElement
+                                   ) -> Optional[Element]:
     """Attempt to resolve a missing reference via intersphinx references.
 
     Resolution is tried in the given inventory with the target as is.
@@ -393,22 +405,26 @@ def resolve_reference_in_inventory(env: BuildEnvironment,
     """
     assert inventory_exists(env, inv_name)
     return _resolve_reference(env, inv_name, InventoryAdapter(env).named_inventory[inv_name],
-                              node, contnode)
+                              False, node, contnode)
 
 
 def resolve_reference_any_inventory(env: BuildEnvironment,
-                                    node: pending_xref,
-                                    contnode: TextElement) -> Optional[Element]:
+                                    honor_disabled_domains: bool,
+                                    node: pending_xref, contnode: TextElement
+                                    ) -> Optional[Element]:
     """Attempt to resolve a missing reference via intersphinx references.
 
     Resolution is tried with the target as is in any inventory.
     """
-    return _resolve_reference(env, None, InventoryAdapter(env).main_inventory, node, contnode)
+    return _resolve_reference(env, None, InventoryAdapter(env).main_inventory,
+                              honor_disabled_domains,
+                              node, contnode)
 
 
 def resolve_reference_detect_inventory(env: BuildEnvironment,
-                                       node: pending_xref,
-                                       contnode: TextElement) -> Optional[Element]:
+                                       honor_disabled_domains: bool,
+                                       node: pending_xref, contnode: TextElement
+                                       ) -> Optional[Element]:
     """Attempt to resolve a missing reference via intersphinx references.
 
     Resolution is tried first with the target as is in any inventory.
@@ -418,7 +434,7 @@ def resolve_reference_detect_inventory(env: BuildEnvironment,
     """
 
     # ordinary direct lookup, use data as is
-    res = resolve_reference_any_inventory(env, node, contnode)
+    res = resolve_reference_any_inventory(env, honor_disabled_domains, node, contnode)
     if res is not None:
         return res
 
@@ -439,7 +455,7 @@ def missing_reference(app: Sphinx, env: BuildEnvironment, node: pending_xref,
                       contnode: TextElement) -> Optional[Element]:
     """Attempt to resolve a missing reference via intersphinx references."""
 
-    return resolve_reference_detect_inventory(env, node, contnode)
+    return resolve_reference_detect_inventory(env, True, node, contnode)
 
 
 def normalize_intersphinx_mapping(app: Sphinx, config: Config) -> None:
@@ -470,6 +486,7 @@ def setup(app: Sphinx) -> Dict[str, Any]:
     app.add_config_value('intersphinx_mapping', {}, True)
     app.add_config_value('intersphinx_cache_limit', 5, False)
     app.add_config_value('intersphinx_timeout', None, False)
+    app.add_config_value('intersphinx_disabled_domains', [], True)
     app.connect('config-inited', normalize_intersphinx_mapping, priority=800)
     app.connect('builder-inited', load_mappings)
     app.connect('missing-reference', missing_reference)
diff --git a/sphinx/templates/quickstart/conf.py_t b/sphinx/templates/quickstart/conf.py_t
index f1da41c4a..4e37f3130 100644
--- a/sphinx/templates/quickstart/conf.py_t
+++ b/sphinx/templates/quickstart/conf.py_t
@@ -108,6 +108,10 @@ html_static_path = ['{{ dot }}static']
 intersphinx_mapping = {
     'python': ('https://docs.python.org/3', None),
 }
+
+# Prevent accidental intersphinx resolution for labels, documents, and other
+# basic cross-references.
+intersphinx_disabled_domains = ['std']
 {%- endif %}
 {%- if 'sphinx.ext.todo' in extensions %}
 
diff --git a/tests/test_ext_intersphinx.py b/tests/test_ext_intersphinx.py
index 2f18748dd..6856c6e62 100644
--- a/tests/test_ext_intersphinx.py
+++ b/tests/test_ext_intersphinx.py
@@ -42,6 +42,12 @@ def reference_check(app, *args, **kwds):
     return missing_reference(app, app.env, node, contnode)
 
 
+def set_config(app, mapping):
+    app.config.intersphinx_mapping = mapping
+    app.config.intersphinx_cache_limit = 0
+    app.config.intersphinx_disabled_domains = []
+
+
 @mock.patch('sphinx.ext.intersphinx.InventoryFile')
 @mock.patch('sphinx.ext.intersphinx._read_from_url')
 def test_fetch_inventory_redirection(_read_from_url, InventoryFile, app, status, warning):
@@ -90,13 +96,12 @@ def test_fetch_inventory_redirection(_read_from_url, InventoryFile, app, status,
 def test_missing_reference(tempdir, app, status, warning):
     inv_file = tempdir / 'inventory'
     inv_file.write_bytes(inventory_v2)
-    app.config.intersphinx_mapping = {
+    set_config(app, {
         'https://docs.python.org/': inv_file,
         'py3k': ('https://docs.python.org/py3k/', inv_file),
         'py3krel': ('py3k', inv_file),  # relative path
         'py3krelparent': ('../../py3k', inv_file),  # relative path, parent dir
-    }
-    app.config.intersphinx_cache_limit = 0
+    })
 
     # load the inventory and check if it's done correctly
     normalize_intersphinx_mapping(app, app.config)
@@ -169,10 +174,9 @@ def test_missing_reference(tempdir, app, status, warning):
 def test_missing_reference_pydomain(tempdir, app, status, warning):
     inv_file = tempdir / 'inventory'
     inv_file.write_bytes(inventory_v2)
-    app.config.intersphinx_mapping = {
+    set_config(app, {
         'https://docs.python.org/': inv_file,
-    }
-    app.config.intersphinx_cache_limit = 0
+    })
 
     # load the inventory and check if it's done correctly
     normalize_intersphinx_mapping(app, app.config)
@@ -210,10 +214,9 @@ def test_missing_reference_pydomain(tempdir, app, status, warning):
 def test_missing_reference_stddomain(tempdir, app, status, warning):
     inv_file = tempdir / 'inventory'
     inv_file.write_bytes(inventory_v2)
-    app.config.intersphinx_mapping = {
+    set_config(app, {
         'cmd': ('https://docs.python.org/', inv_file),
-    }
-    app.config.intersphinx_cache_limit = 0
+    })
 
     # load the inventory and check if it's done correctly
     normalize_intersphinx_mapping(app, app.config)
@@ -242,10 +245,9 @@ def test_missing_reference_stddomain(tempdir, app, status, warning):
 def test_missing_reference_cppdomain(tempdir, app, status, warning):
     inv_file = tempdir / 'inventory'
     inv_file.write_bytes(inventory_v2)
-    app.config.intersphinx_mapping = {
+    set_config(app, {
         'https://docs.python.org/': inv_file,
-    }
-    app.config.intersphinx_cache_limit = 0
+    })
 
     # load the inventory and check if it's done correctly
     normalize_intersphinx_mapping(app, app.config)
@@ -269,10 +271,9 @@ def test_missing_reference_cppdomain(tempdir, app, status, warning):
 def test_missing_reference_jsdomain(tempdir, app, status, warning):
     inv_file = tempdir / 'inventory'
     inv_file.write_bytes(inventory_v2)
-    app.config.intersphinx_mapping = {
+    set_config(app, {
         'https://docs.python.org/': inv_file,
-    }
-    app.config.intersphinx_cache_limit = 0
+    })
 
     # load the inventory and check if it's done correctly
     normalize_intersphinx_mapping(app, app.config)
@@ -291,14 +292,63 @@ def test_missing_reference_jsdomain(tempdir, app, status, warning):
     assert rn.astext() == 'baz()'
 
 
+def test_missing_reference_disabled_domain(tempdir, app, status, warning):
+    inv_file = tempdir / 'inventory'
+    inv_file.write_bytes(inventory_v2)
+    set_config(app, {
+        'inv': ('https://docs.python.org/', inv_file),
+    })
+
+    # load the inventory and check if it's done correctly
+    normalize_intersphinx_mapping(app, app.config)
+    load_mappings(app)
+
+    def case(std_without, std_with, py_without, py_with):
+        def assert_(rn, expected):
+            if expected is None:
+                assert rn is None
+            else:
+                assert rn.astext() == expected
+
+        kwargs = {}
+
+        node, contnode = fake_node('std', 'doc', 'docname', 'docname', **kwargs)
+        rn = missing_reference(app, app.env, node, contnode)
+        assert_(rn, std_without)
+
+        node, contnode = fake_node('std', 'doc', 'inv:docname', 'docname', **kwargs)
+        rn = missing_reference(app, app.env, node, contnode)
+        assert_(rn, std_with)
+
+        # an arbitrary ref in another domain
+        node, contnode = fake_node('py', 'func', 'module1.func', 'func()', **kwargs)
+        rn = missing_reference(app, app.env, node, contnode)
+        assert_(rn, py_without)
+
+        node, contnode = fake_node('py', 'func', 'inv:module1.func', 'func()', **kwargs)
+        rn = missing_reference(app, app.env, node, contnode)
+        assert_(rn, py_with)
+
+    # the base case, everything should resolve
+    assert app.config.intersphinx_disabled_domains == []
+    case('docname', 'docname', 'func()', 'func()')
+
+    # disabled one domain
+    app.config.intersphinx_disabled_domains = ['std']
+    case(None, 'docname', 'func()', 'func()')
+
+    # disabled all domains
+    app.config.intersphinx_disabled_domains = ['all']
+    case(None, 'docname', None, 'func()')
+
+
 @pytest.mark.xfail(os.name != 'posix', reason="Path separator mismatch issue")
 def test_inventory_not_having_version(tempdir, app, status, warning):
     inv_file = tempdir / 'inventory'
     inv_file.write_bytes(inventory_v2_not_having_version)
-    app.config.intersphinx_mapping = {
+    set_config(app, {
         'https://docs.python.org/': inv_file,
-    }
-    app.config.intersphinx_cache_limit = 0
+    })
 
     # load the inventory and check if it's done correctly
     normalize_intersphinx_mapping(app, app.config)
@@ -318,16 +368,15 @@ def test_load_mappings_warnings(tempdir, app, status, warning):
     """
     inv_file = tempdir / 'inventory'
     inv_file.write_bytes(inventory_v2)
-    app.config.intersphinx_mapping = {
+    set_config(app, {
         'https://docs.python.org/': inv_file,
         'py3k': ('https://docs.python.org/py3k/', inv_file),
         'repoze.workflow': ('http://docs.repoze.org/workflow/', inv_file),
         'django-taggit': ('http://django-taggit.readthedocs.org/en/latest/',
                           inv_file),
         12345: ('http://www.sphinx-doc.org/en/stable/', inv_file),
-    }
+    })
 
-    app.config.intersphinx_cache_limit = 0
     # load the inventory and check if it's done correctly
     normalize_intersphinx_mapping(app, app.config)
     load_mappings(app)
@@ -337,7 +386,7 @@ def test_load_mappings_warnings(tempdir, app, status, warning):
 def test_load_mappings_fallback(tempdir, app, status, warning):
     inv_file = tempdir / 'inventory'
     inv_file.write_bytes(inventory_v2)
-    app.config.intersphinx_cache_limit = 0
+    set_config(app, {})
 
     # connect to invalid path
     app.config.intersphinx_mapping = {