Fixes #4895.

The size map size computation for parallel hash sets was invalid.

No review.

3 files changed, 28 insertions, 2 deletions

diff --git a/src/library/scala/collection/mutable/FlatHashTable.scala b/src/library/scala/collection/mutable/FlatHashTable.scala
index 3118d6aa31..0b8ca66c55 100644
--- a/src/library/scala/collection/mutable/FlatHashTable.scala
+++ b/src/library/scala/collection/mutable/FlatHashTable.scala
@@ -231,7 +231,7 @@ trait FlatHashTable[A] extends FlatHashTable.HashUtils[A] {
     else java.util.Arrays.fill(sizemap, 0)
   }
 
-  private[collection] final def totalSizeMapBuckets = if (sizeMapBucketSize < table.length) 1 else table.length / sizeMapBucketSize
+  private[collection] final def totalSizeMapBuckets = (table.length - 1) / sizeMapBucketSize + 1
 
   protected def calcSizeMapSize(tableLength: Int) = (tableLength >> sizeMapBucketBitSize) + 1
 
@@ -264,7 +264,11 @@ trait FlatHashTable[A] extends FlatHashTable.HashUtils[A] {
   }
 
   private[collection] def printSizeMap() {
-    println(sizemap.toList)
+    println(sizemap.mkString("szmap: [", ", ", "]"))
+  }
+
+  private[collection] def printContents() {
+    println(table.mkString("[", ", ", "]"))
   }
 
   protected def sizeMapDisable() = sizemap = null
diff --git a/src/library/scala/collection/mutable/HashSet.scala b/src/library/scala/collection/mutable/HashSet.scala
index 134558ad15..853becbf43 100644
--- a/src/library/scala/collection/mutable/HashSet.scala
+++ b/src/library/scala/collection/mutable/HashSet.scala
@@ -55,11 +55,13 @@ extends Set[A]
   def contains(elem: A): Boolean = containsEntry(elem)
 
   def += (elem: A): this.type = { addEntry(elem); this }
+
   def -= (elem: A): this.type = { removeEntry(elem); this }
 
   override def par = new ParHashSet(hashTableContents)
 
   override def add(elem: A): Boolean = addEntry(elem)
+
   override def remove(elem: A): Boolean = removeEntry(elem).isDefined
 
   override def clear() = clearTable()
diff --git a/test/files/run/t4895.scala b/test/files/run/t4895.scala
new file mode 100644
index 0000000000..14f6761209
--- /dev/null
+++ b/test/files/run/t4895.scala
@@ -0,0 +1,20 @@
+
+
+
+
+object Test {
+
+  def checkPar(sz: Int) {
+    import collection._
+    val hs = mutable.HashSet[Int]() ++ (1 to sz)
+    assert(hs.par.map(_ + 1).seq.toSeq.sorted == (2 to (sz + 1)))
+  }
+
+  def main(args: Array[String]) {
+    for (i <- 0 until 100) checkPar(i)
+    for (i <- 100 until 1000 by 50) checkPar(i)
+    for (i <- 1000 until 10000 by 500) checkPar(i)
+    for (i <- 10000 until 100000 by 5000) checkPar(i)
+  }
+
+}