intersphinx role: new inventory parsing from role name

3 files changed, 71 insertions, 13 deletions

diff --git a/sphinx/ext/intersphinx.py b/sphinx/ext/intersphinx.py
index ce10f1228..2c640925b 100644
--- a/sphinx/ext/intersphinx.py
+++ b/sphinx/ext/intersphinx.py
@@ -489,9 +489,15 @@ class IntersphinxDispatcher(CustomReSTDispatcher):
 
 class IntersphinxRole(SphinxRole):
     def run(self) -> Tuple[List[Node], List[system_message]]:
-        role_name = self.get_role_name(self.name)
+        inventory, name_suffix = self.get_inventory_and_name_suffix(self.name)
+        if inventory and not inventory_exists(self.env, inventory):
+            logger.warning(__('inventory for external cross-reference not found: %s'), inventory,
+                           location=(self.env.docname, self.lineno))
+            return [], []
+
+        role_name = self.get_role_name(name_suffix)
         if role_name is None:
-            logger.warning(__('role not found: %s'), self.name,
+            logger.warning(__('role for external cross-reference not found: %s'), name_suffix,
                            location=(self.env.docname, self.lineno))
             return [], []
 
@@ -499,20 +505,33 @@ class IntersphinxRole(SphinxRole):
         for node in result:
             if isinstance(node, pending_xref):
                 node['intersphinx'] = True
-                node['inventory'] = None
+                node['inventory'] = inventory
 
         return result, messages
 
+    def get_inventory_and_name_suffix(self, name: str) -> Tuple[Optional[str], Optional[str]]:
+        assert name.startswith('external:'), name
+        name = name[9:]
+        inv_names = name.split('+')
+        inventory = None
+        if len(inv_names) > 1:
+            # inv+role
+            # inv+domain:role
+            inventory = inv_names[0]
+            name = name[len(inventory)+1:]
+        return inventory, name
+
     def get_role_name(self, name: str) -> Optional[Tuple[str, str]]:
         names = name.split(':')
-        if len(names) == 2:
-            # :external:role:
-            domain = self.env.temp_data.get('default_domain')
+        if len(names) == 1:
+            # role
+            default_domain = self.env.temp_data.get('default_domain')
+            domain = default_domain.name if default_domain else None
+            role = names[0]
+        elif len(names) == 2:
+            # domain:role:
+            domain = names[0]
             role = names[1]
-        elif len(names) == 3:
-            # :external:domain:role:
-            domain = names[1]
-            role = names[2]
         else:
             return None
 
@@ -559,8 +578,7 @@ class IntersphinxRoleResolver(ReferencesResolver):
             contnode = cast(nodes.TextElement, node[0].deepcopy())
             inv_name = node['inventory']
             if inv_name is not None:
-                if not inventory_exists(self.env, inv_name):
-                    continue
+                assert inventory_exists(self.env, inv_name)
                 newnode = resolve_reference_in_inventory(self.env, inv_name, node, contnode)
             else:
                 newnode = resolve_reference_any_inventory(self.env, False, node, contnode)
diff --git a/tests/roots/test-ext-intersphinx-role/index.rst b/tests/roots/test-ext-intersphinx-role/index.rst
index bb7a6c4f1..5c2cdbd00 100644
--- a/tests/roots/test-ext-intersphinx-role/index.rst
+++ b/tests/roots/test-ext-intersphinx-role/index.rst
@@ -14,8 +14,31 @@
 - ``module10`` is only defined here, but should still not be resolved to:
   :external:py:mod:`module10`
 
-
 - a function in inv:
   :external:py:func:`module1.func`
 - a method, but with old style inventory prefix, which shouldn't work:
   :external:py:meth:`inv:Foo.bar`
+- a non-existing role:
+  :external:py:nope:`something`
+
+.. default-domain:: cpp
+
+- a type where the default domain is used to find the role:
+  :external:type:`std::uint8_t`
+- a non-existing role in default domain:
+  :external:nope:`somethingElse`
+
+- two roles in ``std`` which can be found without a default domain:
+
+  - :external:doc:`docname`
+  - :external:option:`ls -l`
+
+
+- a function with explicit inventory:
+  :external:inv+c:func:`CFunc`
+- a class with explicit non-existing inventory, which also has upper-case in name:
+  :external:invNope+cpp:class:`foo::Bar`
+
+
+- explicit title:
+  :external:cpp:type:`FoonsTitle <foons>`
diff --git a/tests/test_ext_intersphinx.py b/tests/test_ext_intersphinx.py
index ec2aad440..11450e2c3 100644
--- a/tests/test_ext_intersphinx.py
+++ b/tests/test_ext_intersphinx.py
@@ -552,3 +552,20 @@ def test_intersphinx_role(app, warning):
 
     assert html.format('sub/foo.html#module1.func') in content
     assert "WARNING: external py:meth reference target not found: inv:Foo.bar" in wStr
+
+    assert "WARNING: role for external cross-reference not found: py:nope" in wStr
+
+    # default domain
+    assert html.format('index.html#std_uint8_t') in content
+    assert "WARNING: role for external cross-reference not found: nope" in wStr
+
+    # std roles without domain prefix
+    assert html.format('docname.html') in content
+    assert html.format('index.html#cmdoption-ls-l') in content
+
+    # explicit inventory
+    assert html.format('cfunc.html#CFunc') in content
+    #assert "WARNING: inventory for external cross-reference not found: invNope" in wStr
+
+    # explicit title
+    assert html.format('index.html#foons') in content