[TODO] pathutils.`/` can return invalid AbsoluteFile

[timotheecour]

pathutils./ can return invalid AbsoluteFile

Example

import compiler/pathutils
proc main()=
  var a: AbsoluteDir
  let b = "../foo".RelativeFile
  let c: AbsoluteFile = a/b
  echo c

main()

Current Output

../foo

Expected Output

../foo is not absolute so there's a loophole in API

Possible Solution

• making a empty behave as cwd
• throwing an exception is another option

Additional Information

• devel a33b72a
• root cause of successX now correctly shows html output for nim doc, nim jsondoc; fix #13121 #13116 (comment)

Note: I dislike AbsoluteFile,AbsoluteDir,RelativeFile,RelativeDir as I've written in nim-lang/RFCs#71 and I think we can find a better API; at least it's not exposed outside compiler

[Araq]

But I like the design very much, bugs are bugs. Empty behave the same as cwd seems reasonable but who knows what it'll break.

[timotheecour]

IMO the correct fix is to throw instead of implying cwd.
We've already agreed (see #10018 (comment)) it's a bad idea to conflate empty "" (which means uninitialized) with cwd; but while os./ can handle the empty case just fine (returning a relative path), it would be a bug (this bug actually) to return a relative path in pathutils./ ; one of those gotchas with the current design.

[Araq]

Sounds convincing indeed. Let's give it a try.