conftest.py definitions in subdirectories shadow those in parent directories

When there is a conftest.py in a subdirectory that contains a pytest.fixture of the same name as one in a conftest.py file in a parent directory, the fixture in the subdirectory runs for tests in the subdirectory, but the one in the parent does not.

Repro

Create a directory. Put in:

conftest.py

conftest.py

import os
import pytest

@pytest.fixture(autouse=True)
def record_file_attribute(record_property, request):
    file_path = os.path.relpath(request.node.location[0])
    record_property("file", file_path)

test_hello.py

def test_hello(record_property):
    assert True

submod/__init__.py (empty file)

submod/test_hello.py with the same contents as test_hello.py above.

submod/conftest.py with the same contents as test_hello.py above, but with "file" changed to "file2".

Run pytest in the root directory with --junitxml=output.xml. The output will be:

<?xml version="1.0" encoding="utf-8"?>
<testsuites>
  <testsuite name="pytest" errors="0" failures="0" skipped="0" tests="2" time="0.028" timestamp="2023-03-30T11:32:48.799625" hostname="fross-mbp">
    <testcase classname="test_minimal" name="test_hello" file="test_hello.py" line="0" time="0.001">
      <properties>
        <property name="file" value="test_hello.py"/>
      </properties>
    </testcase>
    <testcase classname="submod.test_hello" name="test_other" file="submod/test_hello.py" line="0" time="0.001">
      <properties>
        <property name="file2" value="submod/test_hello.py"/>
      </properties>
    </testcase>
  </testsuite>
</testsuites>

instead of having a file property on both.

pytest version 6.2.5

Reproduce the issue with the root and submod conftest.py files, their test_hello.py files, and pytest --junitxml=output.xml. Compare the generated output.xml properties for both tests, then trace pytest's fixture resolution for parent and subdirectory conftest.py files. Done means both tests retain the expected parent fixture property while the subdirectory fixture behavior remains correct.