Fix inference of instance attributes defined in base class

[nelfin]

Steps

• For new features or bug fixes, add a ChangeLog entry describing what your PR does.
• Write a good description on what the PR does.

Description

Ref #932. The cause of this appears to be failing to specify the
lookupname on the inference context in BaseInstance.igetattr.
Additionally, the context path key was not set in a manner that matched
other usages. This appears to date back to at least 2015 when context
path keys were changed. The usage as a tuple instead of a node with
implict lookupname was changed last in 3d342e8 but the lookup key was
preserved throughout various changes since then.

Type of Changes

	Type
✓	🐛 Bug fix

Related Issue

Closes #932

[cdce8p]

@nelfin Would you mind resolving the merge conflicts? This PR seems like one I can review within the next few days.

[cdce8p]

The change itself LGTM. Just some minor comments regarding the tests.

[cdce8p]

Thanks 🐬

[nelfin]

I know there's no perfect way to manage pull requests on GitHub, but I don't like how it disregarded all of the commit message and instead tells people to refer to this PR link. I'd rather that those messages stayed in the history.

[cdce8p]

I know there's no perfect way to manage pull requests on GitHub, but I don't like how it disregarded all of the commit message and instead tells people to refer to this PR link. I'd rather that those messages stayed in the history.

Not completely sure about that. Up until now, when I merged something I decided on the go what made sense to keep. For this one, as it's just a small bugfix, I chose to remove it. I almost never look at a commit message outside of Github history where the PR is also available so I'm not the best one to judge. If you like, I can try to keep yours if I happen to merge any other of your PRs.

[nelfin]

Not completely sure about that. Up until now, when I merged something I decided on the go what made sense to keep. For this one, as it's just a small bugfix, I chose to remove it.

That's fine, it's not likely to cause too much confusion. To me, the real value in a small bugfix is not the lines itself, but the explanation as to why things broke.

I almost never look at a commit message outside of Github history where the PR is also available so I'm not the best one to judge.

This repository is actually older than GitHub itself so it's probably prudent to keep a "backup".

If you like, I can try to keep yours if I happen to merge any other of your PRs.

If it's not too much trouble.