Delete shared default options after context

petsctools/options.py

@@ -502,11 +502,17 @@ def __init__(self, parameters: dict[str, Any],
         # The parameters to drop from the global options when we leave the
         # inserted_options context. This is everything except for options
         # passed on the command line.
-        to_delete = set(parameters.keys())
+        to_delete = set(parameters.keys()) | set(default_options.keys())
 
+        # Start building parameters from the defaults so
+        # that they will overwritten by any other source.
+        # Start building parameters from the defaults so
+        # that they will overwritten by any other source.
         # Start building parameters from the defaults so
         # that they will overwritten by any other source.
         parameters = default_options | parameters
+        to_delete = set(parameters.keys())
+        to_delete = set(parameters.keys())
         unsafe_options = []
         for full_key, v in self.options_object.getAll().items():
             if full_key.startswith(options_prefix):

tests/test_options.py

@@ -179,6 +179,75 @@ def test_default_options():
     assert options2.parameters["opt4"] == "6"
 
 
+@pytest.mark.skipnopetsc4py
+def test_inserted_options_deletes_default_options():
+    """Check that inserted_options removes the options that the
+    OptionsManager receives through its default options set, and keeps
+    the options that the database already held."""
+    from petsc4py import PETSc
+
+    options = PETSc.Options()
+    options["parent_ksp_type"] = "cg"
+    options["parent_0_pc_type"] = "jacobi"
+    opts_before = dict(options.getAll())
+
+    child = petsctools.OptionsManager(
+        parameters={},
+        options_prefix="parent_0",
+        default_options_set=petsctools.DefaultOptionSet("parent", [0]))
+    assert child.parameters == {"ksp_type": "cg", "pc_type": "jacobi"}
+
+    with child.inserted_options():
+        pass
+
+    assert options.getAll() == opts_before
+
+
+@pytest.mark.skipnopetsc4py
+def test_inserted_options_deletes_defaults_for_multiple_prefixes():
+    """Check shared defaults are removed for sequential child managers."""
+    from petsc4py import PETSc
+
+    options = PETSc.Options()
+    options["parent_ksp_type"] = "cg"
+    default_options_set = petsctools.DefaultOptionSet("parent", [0, 1])
+    children = [
+        petsctools.OptionsManager(
+            parameters={},
+            options_prefix=f"parent_{i}",
+            default_options_set=default_options_set,
+        )
+        for i in (0, 1)
+    ]
+
+    for child in children:
+        key = child.options_prefix + "ksp_type"
+        with child.inserted_options():
+            assert options[key] == "cg"
+        assert key not in options.getAll()
+
+
+@pytest.mark.skipnopetsc4py
+def test_inserted_options_child_option_overrides_default():
+    """Check a child option overrides a shared default while inserted."""
+    from petsc4py import PETSc
+
+    options = PETSc.Options()
+    options["parent_ksp_type"] = "cg"
+    options["parent_1_ksp_type"] = "gmres"
+    opts_before = dict(options.getAll())
+    child = petsctools.OptionsManager(
+        parameters={},
+        options_prefix="parent_1",
+        default_options_set=petsctools.DefaultOptionSet("parent", [0, 1]),
+    )
+
+    assert child.parameters["ksp_type"] == "gmres"
+    with child.inserted_options():
+        assert options["parent_1_ksp_type"] == "gmres"
+    assert options.getAll() == opts_before
+
+
 @pytest.mark.skipnopetsc4py
 def test_python_options_with_manager():
     petsctools.init()