Fix a bug and add a test

src/_pytest/fixtures.py

@@ -1486,7 +1486,12 @@ class FixtureManager:
                     fixturedefs = self.getfixturedefs(argname, parentid)
                     if fixturedefs:
                         arg2fixturedefs[argname] = fixturedefs
-                if argname in arg2fixturedefs:
+                else:
+                    fixturedefs = arg2fixturedefs[argname]
+                if fixturedefs and not (
+                    fixturedefs[-1].func.__name__ == "get_direct_param_fixture_func"
+                    and fixturedefs[-1].baseid == ""
+                ):
                     fixturenames_closure = deduplicate_names(
                         fixturenames_closure + arg2fixturedefs[argname][-1].argnames
                     )

testing/python/fixtures.py

@@ -4619,6 +4619,32 @@ def test_reordering_after_dynamic_parametrize(pytester: Pytester):
     )
 
 
+def test_request_shouldnt_be_in_closure_after_pruning_dep_tree_when_its_not_in_initial_closure(
+    pytester: Pytester,
+):
+    pytester.makepyfile(
+        """
+        import pytest
+
+        def pytest_generate_tests(metafunc):
+            metafunc.parametrize("arg", [0])
+
+        @pytest.fixture()
+        def fixture():
+            pass
+
+        def test(fixture, arg):
+            pass
+        """
+    )
+    result = pytester.runpytest("--setup-show")
+    result.stdout.re_match_lines(
+        [
+            r".+test\[0\] \(fixtures used: arg, fixture\)\.",
+        ],
+    )
+
+
 def test_dont_recompute_dependency_tree_if_no_dynamic_parametrize(pytester: Pytester):
     pytester.makeconftest(
         """

testing/python/show_fixtures_per_test.py

@@ -1,3 +1,4 @@
+import pytest
 from _pytest.pytester import Pytester
 
 
@@ -252,3 +253,39 @@ def test_verbose_include_multiline_docstring(pytester: Pytester) -> None:
             "    Docstring content that extends into a third paragraph.",
         ]
     )
+
+
+@pytest.mark.xfail(
+    reason="python.py::show_fixtures_per_test uses arg2fixturedefs instead of fixtureclosure"
+)
+def test_should_not_show_fixtures_pruned_after_dynamic_parametrization(
+    pytester: Pytester,
+) -> None:
+    pytester.makepyfile(
+        """
+        import pytest
+
+        @pytest.fixture
+        def fixture1():
+            pass
+
+        @pytest.fixture
+        def fixture2(fixture1):
+            pass
+
+        @pytest.fixture
+        def fixture3(fixture2):
+            pass
+
+        def pytest_generate_tests(metafunc):
+            metafunc.parametrize("fixture3", [0])
+
+        def test(fixture3):
+            pass
+    """
+    )
+    result = pytester.runpytest("--fixtures-per-test")
+    result.stdout.re_match_lines(
+        [r"-+ fixtures used by test\[0\] -+", r"-+ \(.+\) -+", r"fixture3 -- .+"],
+        consecutive=True,
+    )