Harden the typer against surprise unapply types.

Closes SI-5078, no review.

2 files changed, 24 insertions, 0 deletions

diff --git a/test/files/neg/t5078.check b/test/files/neg/t5078.check
new file mode 100644
index 0000000000..8f66445b03
--- /dev/null
+++ b/test/files/neg/t5078.check
@@ -0,0 +1,13 @@
+t5078.scala:7: error: an unapply method must accept a single argument.
+    val Foo(x1) = 1
+        ^
+t5078.scala:7: error: recursive value x1 needs type
+    val Foo(x1) = 1
+           ^
+t5078.scala:8: error: an unapply method must accept a single argument.
+    val Foo2(y2) = 2
+        ^
+t5078.scala:8: error: recursive value y2 needs type
+    val Foo2(y2) = 2
+            ^
+four errors found
diff --git a/test/files/neg/t5078.scala b/test/files/neg/t5078.scala
new file mode 100644
index 0000000000..2e727e773d
--- /dev/null
+++ b/test/files/neg/t5078.scala
@@ -0,0 +1,11 @@
+object Foo { def unapply: Option[Int] = Some(42) }
+object Foo2 { def unapply(): Option[Int] = Some(42) }
+
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    val Foo(x1) = 1
+    val Foo2(y2) = 2
+    ()
+  }
+}