5 files changed, 47 insertions, 0 deletions
diff --git a/test/files/pos/bug4840.flags b/test/files/pos/bug4840.flags
new file mode 100644
index 0000000000..eb4d19bcb9
--- /dev/null
+++ b/test/files/pos/bug4840.flags
@@ -0,0 +1 @@
+-optimise
+\ No newline at end of file
diff --git a/test/files/pos/bug4840.scala b/test/files/pos/bug4840.scala
new file mode 100644
index 0000000000..bf44f71d7a
--- /dev/null
+++ b/test/files/pos/bug4840.scala
@@ -0,0 +1,13 @@
+class Crashy {
+  def g(): Option[Any] = None
+
+  def crashy() = {
+    for (_ <- g()) {
+      (null: Any) match {
+        case Some(_) => 5
+        case None    => sys.error("")
+      }
+    }
+  }
+}
+
diff --git a/test/files/run/run-bug4840.check b/test/files/run/run-bug4840.check
new file mode 100644
index 0000000000..cdfc1f911f
--- /dev/null
+++ b/test/files/run/run-bug4840.check
@@ -0,0 +1,2 @@
+Some(5)
+Some(Some(Some(5)))
diff --git a/test/files/run/run-bug4840.flags b/test/files/run/run-bug4840.flags
new file mode 100644
index 0000000000..eb4d19bcb9
--- /dev/null
+++ b/test/files/run/run-bug4840.flags
@@ -0,0 +1 @@
+-optimise
+\ No newline at end of file
diff --git a/test/files/run/run-bug4840.scala b/test/files/run/run-bug4840.scala
new file mode 100644
index 0000000000..dda280fd17
--- /dev/null
+++ b/test/files/run/run-bug4840.scala
@@ -0,0 +1,30 @@
+object Test {
+  def g(x: Boolean): Option[String] = if (x) Some("booya") else None
+
+  def f1() = {
+    for (x <- g(true)) yield {
+      g(false) match {
+        case Some(_) => sys.error("")
+        case None    => 5
+      }
+    }
+  }
+
+  def f2() = {
+    for (x <- g(true) ; y <- g(true) ; z <- g(true)) yield {
+      for (x <- g(true) ; y <- g(true) ; z <- g(true)) yield {
+        g(true) map { _ =>
+          (null: Any) match {
+            case Some(x: Int) => x
+            case _            => 5
+          }
+        }
+      }
+    }
+  }
+
+  def main(args: Array[String]): Unit = {
+    println(f1())
+    println(f2())
+  }
+}