Use FileManager API to get current working directory

[daveinglis]

• FileManager handles long file name prefixes on Windows correctly.
  This keeps any UNC long file prefix (\\?\) out of
  URL that were relative and then resolved to absolute urls.

[daveinglis]

@swift-ci test

[jakepetroules]

Could we add tests for this?

[daveinglis]

test added

[daveinglis]

@swift-ci test

[daveinglis]

@swift-ci test

[daveinglis]

@swift-ci test windows

[daveinglis]

@swift-ci test linux

[daveinglis]

@swift-ci test

[parkera]

Let's identify the user level API this is supposed to change - this CF API should not be used directly, and in any case is all eventually being replaced by Swift code.

[daveinglis]

So the swift API that would be affected was going to have this as well (FileManager.currentDirectoryPath - see swiftlang/swift-foundation#1479) but that PR also cause the NSURL test to fail so it was reverted (swiftlang/swift-foundation#1512) until a fix could be put in place (this).

[daveinglis]

@swift-ci test

[daveinglis]

@parkera Is my last comment clear on where this prefix is originating from? I would like to resurrect this (swiftlang/swift-foundation#1479) foundation change that was reverted once this goes in.

[daveinglis]

@swift-ci test

[daveinglis]

@swift-ci test

[daveinglis]

@swift-ci test windows

[daveinglis]

@swift-ci test windows

[daveinglis]

@parkera @jmschonfeld are we good with the latest changes?

[jmschonfeld]

This LGTM (since as you mentioned there's an existing test that validates the behavior here). Have you been able to test this with your original swift-foundation change to confirm that if we reintroduce the swift-foundation change that the tests here still succeed?

[daveinglis]

Just tried it, so far so good 👍