Fixes SI-6271 - Missing isEmpty override for views.

GenIterableView didn't override isEmpty for views to look at *filtered* iterator, but was instead pulling
unfiltered iterator and causing issues.   Chalk up another bizzare bug to lack of insight/visibility into
linearization and what havoc overriding new methods can spew on our library.

1 files changed, 32 insertions, 0 deletions

diff --git a/test/files/run/t6271.scala b/test/files/run/t6271.scala
new file mode 100644
index 0000000000..8ebf7ad8b5
--- /dev/null
+++ b/test/files/run/t6271.scala
@@ -0,0 +1,32 @@
+object Test extends App {
+  def filterIssue = {
+    val viewed : Iterable[Iterable[Int]] = List(List(0).view).view
+    val filtered = viewed flatMap { x => List( x filter (_ > 0) ) }
+    filtered.iterator.toIterable.flatten
+  }
+  def takenIssue = {
+    val viewed : Iterable[Iterable[Int]] = List(List(0).view).view
+    val filtered = viewed flatMap { x => List( x take 0 ) }
+    filtered.iterator.toIterable.flatten
+  }
+  def droppedIssue = {
+    val viewed : Iterable[Iterable[Int]] = List(List(0).view).view
+    val filtered = viewed flatMap { x => List( x drop 1 ) }
+    filtered.iterator.toIterable.flatten
+  }
+  def flatMappedIssue = {
+    val viewed : Iterable[Iterable[Int]] = List(List(0).view).view
+    val filtered = viewed flatMap { x => List( x flatMap (_ => List()) ) }
+    filtered.iterator.toIterable.flatten
+  }
+  def slicedIssue = {
+    val viewed : Iterable[Iterable[Int]] = List(List(0).view).view
+    val filtered = viewed flatMap { x => List( x slice (2,3) ) }
+    filtered.iterator.toIterable.flatten
+  }
+  filterIssue
+  takenIssue
+  droppedIssue
+  flatMappedIssue
+  slicedIssue
+}