``test_pydoc.test_pydoc`` fails with a ``-R 3:3`` option

[Eclips4]

Bug report

Bug description:

./python.exe -m test -R 3:3 test_pydoc.test_pydoc

The output of the tests is in the attached file.

CPython versions tested on:

CPython main branch

Operating systems tested on:

macOS

output.txt

Linked PRs

• gh-120590: Fix test_pydoc in the refleak hunting mode #120615
• [3.13] gh-120590: Fix test_pydoc in the refleak hunting mode (GH-120615) #120669
• [3.12] gh-120590: Fix test_pydoc in the refleak hunting mode (GH-120615) #120670

[Eclips4]

cc @serhiy-storchaka

[serhiy-storchaka]

It fails because sys.modules['pydoc'] and pydoc (imported at the top of test_pydoc) are not the same. Some pydoc functions reload the module and change sys.modules. The first pass is successful because tests with such side effect are run after tests that use unittest.mock.patch, but the second pass fails.

There are other tests that use unittest.mock.patch, they do not fail, but the second pass do not test what it was intended.

The PR restores sys.modules['pydoc'] after it was modified and adds a check after every test to ensure that it was restored (because we may add new tests in future).