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Diffstat (limited to 'test/files/run/t6900.scala')
-rw-r--r-- | test/files/run/t6900.scala | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/test/files/run/t6900.scala b/test/files/run/t6900.scala new file mode 100644 index 0000000000..a29d388129 --- /dev/null +++ b/test/files/run/t6900.scala @@ -0,0 +1,36 @@ +import annotation.tailrec + +trait Universe { + type T <: AnyRef +} + +final class Bug { + var i = 1 + def stop() = { i -= 1; i < 0 } + // the alias bypasses the fast path in erasures InfoTransformer + // predicated on `TypeMap.noChangeToSymbols` + type Alias = Any + + @tailrec + // So we get two symbols for `universe`, the original on the ValDef + // and a clone in the MethodType of `f`. + def f(universe: Universe, l: Alias): universe.T = { + if (stop()) null.asInstanceOf[universe.T] else f(universe, null) + } + + @tailrec + def g(universe: Universe)(l: Alias): universe.T = { + if (stop()) null.asInstanceOf[universe.T] else g(universe)(l) + } + + @tailrec + def h(universe: Universe)(l: List[universe.T]): List[universe.T] = { + if (stop()) Nil else h(universe)(l) + } +} + +object Test extends App { + assert(new Bug().f(null, null) == null) + assert(new Bug().g(null)(null) == null) + assert(new Bug().h(null)(null) == Nil) +}
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