fix: passing ConjunctiveGraph as namespace_manager (#2073)

pass the NamespaceManager of the ConjunctiveGraph as namespace_manager of the Graph created by the get_context() method instead of the ConjunctiveGraph object itself.

CHANGELOG.md

@@ -21,6 +21,22 @@ CHANGE BARRIER is intended to reduce the potential for merge conflicts
 and will be removed for release.
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+ <!-- --> 
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+ <!-- CHANGE BARRIER: START --> 
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+ - Fixes passing `NamespaceManager` in `ConjunctiveGraph`'s method `get_context()`. 
+   The `get_context()` method will now pass the `NamespaceManager` of `ConjunctiveGraph` to the `namespace_manager` attribute of the newly created context graph, instead of the `ConjunctiveGraph` object itself. This cleans up an old FIXME commment.
+   [PR #2073](https://github.com/RDFLib/rdflib/pull/2073). 
+
+<!-- -->
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+<!-- CHANGE BARRIER: END -->
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rdflib/graph.py

@@ -1915,9 +1915,8 @@ def get_context(
 
         identifier must be a URIRef or BNode.
         """
-        # TODO: FIXME - why is ConjunctiveGraph passed as namespace_manager?
         return Graph(
-            store=self.store, identifier=identifier, namespace_manager=self, base=base  # type: ignore[arg-type]
+            store=self.store, identifier=identifier, namespace_manager=self.namespace_manager, base=base  # type: ignore[arg-type]
         )
 
     def remove_context(self, context):

test/test_conjunctivegraph/test_conjunctive_graph.py

@@ -6,6 +6,7 @@
 import pytest
 
 from rdflib import ConjunctiveGraph, Graph
+from rdflib.namespace import NamespaceManager
 from rdflib.parser import StringInputSource
 from rdflib.term import BNode, Identifier, URIRef
 
@@ -47,6 +48,17 @@ def test_quad_contexts():
         assert isinstance(q[3], Graph)
 
 
+def test_context_namespaces():
+    cg = ConjunctiveGraph()
+    a = URIRef("urn:a")
+    ns = URIRef("http://example.org/")
+    cg.bind("ex", ns)
+    g = cg.get_context(a)
+
+    assert type(g.namespace_manager) is NamespaceManager
+    assert ("ex", ns) in g.namespace_manager.namespaces()
+
+
 def get_graph_ids_tests():
     def check(kws):
         cg = ConjunctiveGraph()