---

yaml
---
r: 131544
b: refs/heads/dist-snap
c: 7a7ae99
h: refs/heads/master
v: v3

Author: apoelstra

[refs]

@@ -6,7 +6,7 @@ refs/heads/try: 457a3c991d79b971be07fce75f9d0c12848fb37c
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
 refs/heads/try2: 147ecfdd8221e4a4d4e090486829a06da1e0ca3c
-refs/heads/dist-snap: a698b81ebfe02a614f9b41e68c6b604597a81229
+refs/heads/dist-snap: 7a7ae993ce694bf75a11632b394916e055a4d8ec
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503
 refs/heads/try3: 9387340aab40a73e8424c48fd42f0c521a4875c0

branches/dist-snap/src/libcollections/bitv.rs

@@ -515,9 +515,10 @@ impl BitvSet {
     /// Grows the vector to be able to store bits with indices `[0, size - 1]`
     fn grow(&mut self, size: uint) {
         let &BitvSet(ref mut bitv) = self;
+        let old_size = bitv.storage.len();
         let size = (size + uint::BITS - 1) / uint::BITS;
-        if bitv.storage.len() < size {
-            bitv.storage.grow(size, &0);
+        if old_size < size {
+            bitv.storage.grow(size - old_size, &0);
         }
     }
 
@@ -1253,14 +1254,22 @@ mod tests {
 
     #[test]
     fn test_bitv_set_basic() {
+        // calculate nbits with uint::BITS granularity
+        fn calc_nbits(bits: uint) -> uint {
+            uint::BITS * ((bits + uint::BITS - 1) / uint::BITS)
+        }
+
         let mut b = BitvSet::new();
+        assert_eq!(b.capacity(), calc_nbits(0));
         assert!(b.insert(3));
+        assert_eq!(b.capacity(), calc_nbits(3));
         assert!(!b.insert(3));
         assert!(b.contains(&3));
         assert!(b.insert(4));
         assert!(!b.insert(4));
         assert!(b.contains(&3));
         assert!(b.insert(400));
+        assert_eq!(b.capacity(), calc_nbits(400));
         assert!(!b.insert(400));
         assert!(b.contains(&400));
         assert_eq!(b.len(), 3);