Fix various commands asking for a password

[johnf]

Summary

Commands like publish were asking for a password instead of using the token in .npmrc.

The core code path that was causing the issue is https://github.com/yarnpkg/yarn/blob/master/src/registries/npm-registry.js#L218-L221

// If sending a request to the Yarn registry, we must also send it the auth token for the npm registry
if (baseRegistry === YARN_REGISTRY) {
  registries.push(DEFAULT_REGISTRY);
}

The problem was baseRegistry = "https://registry.yarnpkg.com" while YARN_REGISTRY = "https://registry.yarnpkg.com/". Notice the trailing slash.

I've reverted the code added in 3382071#diff-b053bee294c216269844e5874039b6caR172
which solves the problem. Unclear to me why it was added though.

Test plan

yarn publish no longer asks for a password.

[arcanis]

Ping @lumaxis? Do you remind the rational behind this change?

[johnf]

@lumaxis @arcanis ping

Should I rewrite this to just make this bit of code above work instead of the current change?
This would remove any possible side effects.

[lumaxis]

@arcanis @johnf Heya 👋 Sorry for the slow response on this, was out sick last week and am only slowly catching up on email.
I didn't add this specific change myself as I was also partly building on top of the work of someone else. 😕

[arcanis]

No problem, thanks! Let's merge this then, all tests are green so we can be reasonably confident this won't break anything :)