diff options
| -rw-r--r-- | src/library/scala/collection/mutable/BitSet.scala | 6 | ||||
| -rw-r--r-- | test/junit/scala/collection/mutable/BitSetTest.scala | 9 |
2 files changed, 13 insertions, 2 deletions
diff --git a/src/library/scala/collection/mutable/BitSet.scala b/src/library/scala/collection/mutable/BitSet.scala index 78150b5e88..e92d48cfeb 100644 --- a/src/library/scala/collection/mutable/BitSet.scala +++ b/src/library/scala/collection/mutable/BitSet.scala @@ -121,8 +121,10 @@ class BitSet(protected final var elems: Array[Long]) extends AbstractSet[Int] * @return the bitset itself. */ def &= (other: BitSet): this.type = { - ensureCapacity(other.nwords - 1) - for (i <- 0 until other.nwords) + // Different from other operations: no need to ensure capacity because + // anything beyond the capacity is 0. Since we use other.word which is 0 + // off the end, we also don't need to make sure we stay in bounds there. + for (i <- 0 until nwords) elems(i) = elems(i) & other.word(i) this } diff --git a/test/junit/scala/collection/mutable/BitSetTest.scala b/test/junit/scala/collection/mutable/BitSetTest.scala index 8d164b50d4..d56cc45601 100644 --- a/test/junit/scala/collection/mutable/BitSetTest.scala +++ b/test/junit/scala/collection/mutable/BitSetTest.scala @@ -19,4 +19,13 @@ class BitSetTest { bitSet &~= bitSet assert(bitSet.toBitMask.length == size, "Capacity of bitset changed after &~=") } + + @Test def test_SI8917() { + val bigBitSet = BitSet(1, 100, 10000) + val littleBitSet = BitSet(100) + bigBitSet &= littleBitSet + assert(!(bigBitSet contains 10000), "&= not applied to the full bitset") + littleBitSet &= bigBitSet + assert(littleBitSet.toBitMask.length < bigBitSet.toBitMask.length, "Needlessly extended the size of bitset on &=") + } } |