Odd type error in 2.6.0-RC2.

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Compiling the following code:

trait X {
    case class Foo();
    object Bar {
       def unapply(foo:Foo):Boolean = false;
    }
}
object Y extends X {
   val foo = Foo()
   foo match {
     case Bar() => println("matched bar!");
   }
}

produces a type mismatch with the following message:

<console>:8: error: type mismatch;
found   : Y.this.Foo
required: X.this.Foo
     case Bar() => println("matched bar!");
          ^

But if instead of an object, we make a subclass with the same exact code, as in:

class Z extends X {
   val foo = Foo()
   foo match {
     case Bar() => println("matched bar!");
   }
}

It compiles and runs normally.

Also, the same code does not present any errors either in 2.6.0-RC1 or in 2.5.1.

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-44?orig=1
Reporter: Commit Message Bot (anonymous)

[scabug]

@odersky said:
Why has the bug been assigned to me? Is there any evidence it is my changes between RC1 and RC2 that did this? I don�t think I did any unapply-related changes.

-- Martin

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@burakemir said:
my bad. fixed in r12795. the original changes were fixes for Philipp's unapply bugs, i verified that these still work with test cases unapplyVal.scala (hopefully they cover enough).

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@odersky said:
Milestone 2.6.0 deleted