Adds comments for #3471, and a test case which ...

Adds comments for #3471, and a test case which should have been added
earlier. Review by extempore.

1 files changed, 1 insertions, 1 deletions

diff --git a/test/files/run/groupby.scala b/test/files/run/groupby.scala
index 895410e34d..a751e65e80 100644
--- a/test/files/run/groupby.scala
+++ b/test/files/run/groupby.scala
@@ -10,7 +10,7 @@ object Test {
     val v1 = map(0)
     val v2 = map(0)
     // this should hold, of course, assuming also that group by returns a regular
-    // map implementation, and does nothing fancy - and it should default just a
+    // map implementation, and does nothing fancy - and it should return just a
     // hash map by default.
     assert(v1 eq v2)
   }