Restored ability to connect IPv6-only host.

[asvetlov]

Fixes #6195

[codecov]

Codecov Report

Merging #6309 (da9c264) into master (7f32513) will increase coverage by 0.01%.
The diff coverage is 62.50%.

@@            Coverage Diff             @@
##           master    #6309      +/-   ##
==========================================
+ Coverage   93.30%   93.31%   +0.01%     
==========================================
  Files         103      103              
  Lines       30366    30369       +3     
  Branches     2730     2731       +1     
==========================================
+ Hits        28333    28340       +7     
+ Misses       1857     1852       -5     
- Partials      176      177       +1     

Flag	Coverage Δ
unit	93.24% <62.50%> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
aiohttp/resolver.py	64.00% <57.14%> (+2.29%)	⬆️
tests/test_resolver.py	70.07% <100.00%> (ø)
tests/test_connector.py	95.70% <0.00%> (+0.26%)	⬆️

---

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[patchback]

Backport to 3.8: 💔 cherry-picking failed — conflicts found

❌ Failed to cleanly apply a370cf4 on top of patchback/backports/3.8/a370cf4acdb0d30cc2099d1c9e4a70db9c126c9f/pr-6309

Backporting merged PR #6309 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/3.8/a370cf4acdb0d30cc2099d1c9e4a70db9c126c9f/pr-6309 upstream/3.8

4. Now, cherry-pick PR Restored ability to connect IPv6-only host. #6309 contents into that branch:

   $ git cherry-pick -x a370cf4acdb0d30cc2099d1c9e4a70db9c126c9f

   If it'll yell at you with something like fatal: Commit a370cf4acdb0d30cc2099d1c9e4a70db9c126c9f is a merge but no -m option was given., add -m 1 as follows intead:

   $ git cherry-pick -m1 -x a370cf4acdb0d30cc2099d1c9e4a70db9c126c9f

5. At this point, you'll probably encounter some merge conflicts. You must
   resolve them in to preserve the patch from PR Restored ability to connect IPv6-only host. #6309 as close to the
   original as possible.
6. Push this branch to your fork on GitHub:

   $ git push origin patchback/backports/3.8/a370cf4acdb0d30cc2099d1c9e4a70db9c126c9f/pr-6309

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 3.9: 💔 cherry-picking failed — conflicts found

❌ Failed to cleanly apply a370cf4 on top of patchback/backports/3.9/a370cf4acdb0d30cc2099d1c9e4a70db9c126c9f/pr-6309

Backporting merged PR #6309 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/3.9/a370cf4acdb0d30cc2099d1c9e4a70db9c126c9f/pr-6309 upstream/3.9

4. Now, cherry-pick PR Restored ability to connect IPv6-only host. #6309 contents into that branch:

   $ git cherry-pick -x a370cf4acdb0d30cc2099d1c9e4a70db9c126c9f

   If it'll yell at you with something like fatal: Commit a370cf4acdb0d30cc2099d1c9e4a70db9c126c9f is a merge but no -m option was given., add -m 1 as follows intead:

   $ git cherry-pick -m1 -x a370cf4acdb0d30cc2099d1c9e4a70db9c126c9f

5. At this point, you'll probably encounter some merge conflicts. You must
   resolve them in to preserve the patch from PR Restored ability to connect IPv6-only host. #6309 as close to the
   original as possible.
6. Push this branch to your fork on GitHub:

   $ git push origin patchback/backports/3.9/a370cf4acdb0d30cc2099d1c9e4a70db9c126c9f/pr-6309

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.

[asvetlov]

Backported by 8adddad and a6056fb