SI-9254 UnrolledBuffer appends in wrong position

Fixed two bugs in insertion (insertAll of Unrolled):

1. Incorrect recursion leading to an inability to insert past the first chunk
2. Incorect repositioning of `lastptr` leading to strange `append` behavior after early insertion

Added tests checking that both of these things now work.

Also added a comment that "waterlineDelim" is misnamed.  But we can't fix it now--it's part of the public API.  (Shouldn't be, but it is.)

1 files changed, 25 insertions, 0 deletions

diff --git a/test/junit/scala/collection/mutable/UnrolledBufferTest.scala b/test/junit/scala/collection/mutable/UnrolledBufferTest.scala
new file mode 100644
index 0000000000..8660b6cbc1
--- /dev/null
+++ b/test/junit/scala/collection/mutable/UnrolledBufferTest.scala
@@ -0,0 +1,25 @@
+package scala.collection.mutable
+
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+import org.junit.Test
+
+@RunWith(classOf[JUnit4])
+class UnrolledBufferTestTest {
+  @Test
+  def test_SI9254_original() {
+    val b = new UnrolledBuffer[Int]()
+    (1 to 16).foreach(i => b append i)
+    b.insert(0,-1)
+    b append 17
+    assert(b sameElements (Seq(-1) ++ (1 to 16) ++ Seq(17)))
+  }
+
+  @Test
+  def test_SI9254_additional() {
+    val b = new UnrolledBuffer[Int]()
+    (1 to 100).foreach(i => b append i)
+    b.insert(40, -1)
+    assert(b sameElements((1 to 40) ++ Seq(-1) ++ (41 to 100)))
+  }
+}