SI-8330: Mismatch in stack heights

The SI-8233 / 9506d52 missed one case when we need to DROP a null from
a stack: when unboxed Unit is an expected type. If we forgot to do that
in a context where two branches were involved we could end up with
unbalanced stack sizes.

Let's fix that omission and a test covering that specific case to the
original test for SI-8233.

Fixes SI-8330.

1 files changed, 14 insertions, 1 deletions

diff --git a/test/files/run/t8233-bcode.scala b/test/files/run/t8233-bcode.scala
index fae1c2b702..72d013e553 100644
--- a/test/files/run/t8233-bcode.scala
+++ b/test/files/run/t8233-bcode.scala
@@ -11,8 +11,21 @@ object Test {
     bar(a)
   }
 
-  def main(args: Array[String]) = {
+  /** Check SI-8330 for details */
+  def expectedUnitInABranch(b: Boolean): Boolean = {
+    if (b) {
+      val x = 12
+      ()
+    } else {
+      // here expected type is (unboxed) Unit
+      null
+    }
+    true
+  }
+
+  def main(args: Array[String]): Unit = {
     try { nullReference } catch { case _: NoSuchElementException => }
     literal
+    expectedUnitInABranch(true)
   }
 }