Fix problem in eta expansion.

Failure to do a widen caused by-name parameters to go undetected.

2 files changed, 20 insertions, 0 deletions

diff --git a/tests/run/t5610a.check b/tests/run/t5610a.check
new file mode 100644
index 000000000..2aa46b3b9
--- /dev/null
+++ b/tests/run/t5610a.check
@@ -0,0 +1 @@
+Stroke a kitten
diff --git a/tests/run/t5610a.scala b/tests/run/t5610a.scala
new file mode 100644
index 000000000..3787c0984
--- /dev/null
+++ b/tests/run/t5610a.scala
@@ -0,0 +1,19 @@
+object Test extends dotty.runtime.LegacyApp {
+  class Result(_str: => String) {
+    lazy val str = _str
+  }
+
+  def foo(str: => String)(i: Int) = new Result(str)
+
+  def bar(f: Int => Result) = f(42)
+
+  var test: String = null
+  val result = bar(foo(test))
+  test = "bar"
+
+  if (result.str == null) {
+    println("Destroy ALL THE THINGS!!!")
+  } else {
+    println("Stroke a kitten")
+  }
+}