Fix Link-Local IPv6 Flags in the Resolver

[GitNMLee]

Based on commit c48f2d1, the original use of the NI_NUMERICSERV and NI_NUMERICHOST flags was correct for the getnameinfo() call. As of 38dd9b8 the incorrect flags are now being used. Changed AI_* flags back to NI_* flags. Changed corresponding test.

Related issue number

Fixes #9028

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.30%. Comparing base (e8d8e28) to head (e8a9150).
Report is 1065 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #9032   +/-   ##
=======================================
  Coverage   98.30%   98.30%           
=======================================
  Files         107      107           
  Lines       34355    34362    +7     
  Branches     4066     4066           
=======================================
+ Hits        33771    33778    +7     
  Misses        412      412           
  Partials      172      172           

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OS-Linux	97.85% <100.00%> (+<0.01%)	⬆️
OS-Windows	96.26% <88.88%> (+<0.01%)	⬆️
OS-macOS	97.53% <100.00%> (+<0.01%)	⬆️
Py-3.10.11	97.63% <100.00%> (+<0.01%)	⬆️
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Py-3.9.13	97.52% <100.00%> (+<0.01%)	⬆️
Py-3.9.19	97.46% <100.00%> (+<0.01%)	⬆️
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[Dreamsorcerer]

@bdraco is probably more familiar with this than me, but I think this looks right.

I'm also wondering if we can have a test that actually produces the exception in the original bug report?

[bdraco]

Looks like a good fix to me. 👍

Good catch

[bdraco]

Would be good to get a test for this case as well

[GitNMLee]

Would be good to get a test for this case as well

The test that I changed in my commit seems to cover this case: ed9c04b#diff-4cbff640f1fc708fb7f2d3e79ac97f24cfe22063bad7ce6f67ab97b5b5171a0bL140
Sorry, just realized that test is for the AsyncResolver, not the ThreadedResolver. I will add to an existing test to check that the correct flags are called.

Would it be best to add a test that has a mock side effect that causes the exception?

[bdraco]

Would be good to get a test for this case as well

The test that I changed in my commit seems to cover this case: ed9c04b#diff-4cbff640f1fc708fb7f2d3e79ac97f24cfe22063bad7ce6f67ab97b5b5171a0bL140 Sorry, just realized that test is for the AsyncResolver, not the ThreadedResolver. I will add to an existing test to check that the correct flags are called.

Would it be best to add a test that has a mock side effect that causes the exception?

I would try to keep the mocking an minimal as possible but avoid doing any network I/O

[GitNMLee]

Put up another commit with an alteration of an existing test and some various formatting errors fixed. I did not add a test for the behavior described in the bug report as that requires network I/O and/or testing the socket library, which I'm not sure makes sense here.

[bdraco]

Thanks @GitNMLee

[patchback]

Backport to 3.10: 💔 cherry-picking failed — conflicts found

❌ Failed to cleanly apply c693a81 on top of patchback/backports/3.10/c693a816ce84d46c445841c707f23e31f174cf28/pr-9032

Backporting merged PR #9032 into master

1. Ensure you have a local repo clone of your fork. Unless you cloned it
   from the upstream, this would be your origin remote.
2. Make sure you have an upstream repo added as a remote too. In these
   instructions you'll refer to it by the name upstream. If you don't
   have it, here's how you can add it:

   $ git remote add upstream https://github.com/aio-libs/aiohttp.git

3. Ensure you have the latest copy of upstream and prepare a branch
   that will hold the backported code:

   $ git fetch upstream
   $ git checkout -b patchback/backports/3.10/c693a816ce84d46c445841c707f23e31f174cf28/pr-9032 upstream/3.10

4. Now, cherry-pick PR Fix Link-Local IPv6 Flags in the Resolver #9032 contents into that branch:

   $ git cherry-pick -x c693a816ce84d46c445841c707f23e31f174cf28

   If it'll yell at you with something like fatal: Commit c693a816ce84d46c445841c707f23e31f174cf28 is a merge but no -m option was given., add -m 1 as follows instead:

   $ git cherry-pick -m1 -x c693a816ce84d46c445841c707f23e31f174cf28

5. At this point, you'll probably encounter some merge conflicts. You must
   resolve them in to preserve the patch from PR Fix Link-Local IPv6 Flags in the Resolver #9032 as close to the
   original as possible.
6. Push this branch to your fork on GitHub:

   $ git push origin patchback/backports/3.10/c693a816ce84d46c445841c707f23e31f174cf28/pr-9032

7. Create a PR, ensure that the CI is green. If it's not — update it so that
   the tests and any other checks pass. This is it!
   Now relax and wait for the maintainers to process your pull request
   when they have some cycles to do reviews. Don't worry — they'll tell you if
   any improvements are necessary when the time comes!

🤖 @patchback
I'm built with octomachinery and
my source is open — https://github.com/sanitizers/patchback-github-app.

[patchback]

Backport to 3.11: 💚 backport PR created

✅ Backport PR branch: patchback/backports/3.11/c693a816ce84d46c445841c707f23e31f174cf28/pr-9032

Backported as #9047

🤖 @patchback
I'm built with octomachinery and
my source is open — https://github.com/sanitizers/patchback-github-app.