Handle renamed dependencies coming from Cargo

[alexcrichton]

This commit is intended to be coupled with
rust-lang/cargo#5993 where Cargo will start sending the
registry more information about locally renamed crates to persist into the
index.

[alexcrichton]

Note that this likely shouldn't be merged until rust-lang/cargo#5993 is decided on

[Eh2406]

Sorry for being out of the loop, why does the index need to know what a crate chose to rename a dependency to?

[alexcrichton]

Ah no worries, I thought the same as you! With features, however, it becomes significant because the implicit feature name for the dependency is named after the left-hand-side of what you write in Cargo.toml, which isn't the package name (which is what we're publishing right now)

[Eh2406]

So if I have an optional dependency on serde = "1" that I have renamed to serde1 then the feature will be called serde1? Has the feature part of the resolver ben tealt to read that correctly?

[alexcrichton]

Correct yeah! To do that you'd do serde1 = { version = "1", package = "serde" }, and there should be tests yeah in Cargo for having this plumbed everywhere inside Cargo at least

[alexcrichton]

Ok it looks like we'd like to merge rust-lang/cargo#5993, in light of that r? on this PR to get it merged?

[carols10cents]

Could you add some tests please, that the correct value is written to the index, like this test? I want to make sure we don't break this :)

[carols10cents]

Tests please! :)

[alexcrichton]

Now with a test!

[carols10cents]

Yay tests! Thank you!

bors: r+

[bors-voyager]

Build succeeded

• continuous-integration/travis-ci/push

[carols10cents]

And I've deployed this!