Account for changes in fixture dependencies properly

changelog/14103.bugfix.rst

@@ -0,0 +1 @@
+Fixtures are now rebuilt when param changes for a fixture they depend on, if the dependency is via ``request.getfixturevalue()``.

changelog/14114.bugfix.rst

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+An exception from ``pytest_fixture_post_finalizer`` no longer prevents fixtures from being torn down, causing additional errors in the following tests.

changelog/2043.bugfix.rst

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+If a fixture depends on a fixture that becomes hidden in a test (compared to the previous test), the hidden fixture definition is no longer executed.

changelog/4871.improvement.rst

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+Garbage finalizers for fixture teardown are no longer accumulated in nodes and fixtures.
+
+:func:`Node.addfinalizer <_pytest.nodes.Node.addfinalizer>` and ``request.addfinalizer()`` now return a handle that allows to remove the finalizer.

changelog/5848.improvement.rst

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+``pytest_fixture_post_finalizer`` is no longer called extra times for the same fixture teardown.

changelog/9287.bugfix.rst

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+Teardown of parametrized fixtures now happens in the teardown stage of the test before the parameter changes.
+
+Previously teardown would happen in the setup stage of the test where the parameter changes.
+
+If a test forces teardown of a parametrized fixture, e.g. using ``request.getfixturevalue()``, it instead fails. An example of such test:
+
+.. code-block:: pytest
+
+    # conftest.py
+    import pytest
+
+    @pytest.hookimpl(wrapper=True, tryfirst=True)
+    def pytest_collection_modifyitems(items):
+        # Disable built-in test reordering.
+        original_items = items[:]
+        yield
+        items[:] = original_items
+
+    # test_invalid.py
+    import pytest
+
+    @pytest.fixture(scope="session")
+    def foo(request):
+        return getattr(request, "param", "default")
+
+    @pytest.mark.parametrize("foo", [1], indirect=True)
+    def test_a(foo):
+        assert foo == 1
+
+    def test_b(request):
+        request.getfixturevalue("foo")
+
+    @pytest.mark.parametrize("foo", [1], indirect=True)
+    def test_c(foo):
+        assert foo == 1
+
+This produces the following error:
+
+.. code-block:: console
+
+    Parameter for the requested fixture changed unexpectedly in test:
+        test_invalid.py::test_b
+    Requested fixture 'foo' defined in:
+        test_invalid.py:4
+
+    Previous parameter value: 1
+    New parameter value: None

doc/en/reference/reference.rst

@@ -993,6 +993,13 @@ ExitCode
     :members:
 
 
+FinalizerHandle
+~~~~~~~~~~~~~~~
+
+.. autoclass:: pytest.FinalizerHandle()
+    :members:
+
+
 FixtureDef
 ~~~~~~~~~~