From 267226c3655ae2bdffd3cfd350be675501a35a33 Mon Sep 17 00:00:00 2001
From: Iwan Aucamp <aucampia@gmail.com>
Date: Sun, 10 Oct 2021 23:07:43 +0200
Subject: [PATCH 1/2] Export DCMITYPE

Not sure what went wrong here but for some reason master branch tries to
export DCMITYPE without also importing it.
---
 rdflib/__init__.py           | 1 +
 rdflib/namespace/__init__.py | 1 +
 2 files changed, 2 insertions(+)

diff --git a/rdflib/__init__.py b/rdflib/__init__.py
index 386d14eb8..9b8daeb0e 100644
--- a/rdflib/__init__.py
+++ b/rdflib/__init__.py
@@ -167,6 +167,7 @@
     CSVW,
     DC,
     DCAT,
+    DCMITYPE,
     DCTERMS,
     DOAP,
     FOAF,
diff --git a/rdflib/namespace/__init__.py b/rdflib/namespace/__init__.py
index 86dbdba4d..0487a55da 100644
--- a/rdflib/namespace/__init__.py
+++ b/rdflib/namespace/__init__.py
@@ -701,6 +701,7 @@ def get_longest_namespace(trie, value):
 from rdflib.namespace._CSVW import CSVW
 from rdflib.namespace._DC import DC
 from rdflib.namespace._DCAT import DCAT
+from rdflib.namespace._DCMITYPE import DCMITYPE
 from rdflib.namespace._DCTERMS import DCTERMS
 from rdflib.namespace._DOAP import DOAP
 from rdflib.namespace._FOAF import FOAF

From ffff25d3afcb48a9ac23aa52cb367ebb670d4035 Mon Sep 17 00:00:00 2001
From: Iwan Aucamp <aucampia@gmail.com>
Date: Sun, 10 Oct 2021 22:31:33 +0200
Subject: [PATCH 2/2] Make Store.namespaces an empty generator

90f6fe5 changed

```python
class Store:
    def namespaces(self):
	""" """
	if False:
	    yield None
```

to

```python
class Store:
    def namespaces(self):
	""" """
```

This resulted in `Store.namespaces` no longer being an emtpy generator
by default (see https://stackoverflow.com/q/13243766).

The reason it was removed is because it is unreachable code, however I
did not consider that it would make the function an empty generator.

The reason why `if False: yield None` made it an empty generator is
because the presence of the yield keyword informs CPython that a
function is a generator:
https://www.python.org/dev/peps/pep-0255/#why-a-new-keyword-for-yield-why-not-a-builtin-function-instead

There are several ways of making an empty generator:

- `if False: yield`
- `return` and `yield`
- `yield from ()`
- ... more

Both `if False: yield` and `return`; `yield` results in same bytecode
however, which is that of an empty function, and they are both equally
confusing I would say.

`yield from ()` is somewhat clearer, but the bytecode of the funciton
looks very different from an empty function (see https://stackoverflow.com/a/61496399)

So the best option I see is to just put back what was there and add a
comment and a test to prevent the issue from re-occuring.
---
 rdflib/store.py    |  5 +++++
 test/test_store.py | 25 +++++++++++++++++++++++++
 2 files changed, 30 insertions(+)
 create mode 100644 test/test_store.py

diff --git a/rdflib/store.py b/rdflib/store.py
index 915ca57ad..a7aa8d0b0 100644
--- a/rdflib/store.py
+++ b/rdflib/store.py
@@ -364,6 +364,11 @@ def namespace(self, prefix):
 
     def namespaces(self):
         """ """
+        # This is here so that the function becomes an empty generator.
+        # See https://stackoverflow.com/q/13243766 and
+        # https://www.python.org/dev/peps/pep-0255/#why-a-new-keyword-for-yield-why-not-a-builtin-function-instead
+        if False:
+            yield None  # type: ignore[unreachable]
 
     # Optional Transactional methods
 
diff --git a/test/test_store.py b/test/test_store.py
new file mode 100644
index 000000000..d4d8d0a8a
--- /dev/null
+++ b/test/test_store.py
@@ -0,0 +1,25 @@
+import unittest
+from rdflib import Graph
+from rdflib.store import Store
+from rdflib.namespace import NamespaceManager
+
+
+class TestAbstractStore(unittest.TestCase):
+    def test_namespaces(self):
+        """
+        This tests that Store.namespaces is an empty generator.
+        """
+        store = Store()
+        self.assertEqual(list(store.namespaces()), [])
+
+    def test_namespaces_via_manager(self):
+        """
+        This tests that NamespaceManager.namespaces works correctly with an
+        abstract Store.
+        """
+        namespace_manager = NamespaceManager(Graph(store=Store()))
+        self.assertEqual(list(namespace_manager.namespaces()), [])
+
+
+if __name__ == "__main__":
+    unittest.main()