Else branches carry the If's rather than their own position

[gsps]

Here's a test that can be dropped in TreeInfoTest.scala (for the lack of a more appropriate existing test suite) to demonstrate the faulty behavior. In particular, ifTree.pos == elsep.pos holds.

@Test
def testElseBranchPosition = 
  checkCompile("frontend", "class A { def f(x: Int): Boolean = if (x < 0) true else false}") {
    (tree, context) =>
      implicit val ctx = context
      val fTree   = tree.find(tree => tree.symbol.name == termName("f")).get.asInstanceOf[DefDef]
      val ifTree  = fTree.rhs.asInstanceOf[If]
      val (cond, thenp, elsep) = (ifTree.cond, ifTree.thenp, ifTree.elsep)
      assertTrue(ifTree.pos.start < cond.pos.start)
      assertTrue(cond.pos.start   < thenp.pos.start)
      assertTrue(thenp.pos.start  < elsep.pos.start)
  }

The problem originates from the typedIf(...) in Typer overriding the else branch's position even when the else branch was provided by the user. Unless I'm mistaken, this should be the two-character fix:
val elsep1 = typed(tree.elsep orElse(untpd.unitLiteral withPos tree.pos), pt)

[odersky]

Thanks for pointing this out! That's indeed the right fix. Would you like to do a PR with it?

[nicolasstucki]

@jvican is this issue completely fixed?

[jvican]

Yes, I forgot to add the test in the PR, I will tomorrow.