From e4c39d49fb322169c2932fc10b0c5544318add78 Mon Sep 17 00:00:00 2001
From: Tyler Treat <ttreat31@gmail.com>
Date: Tue, 8 May 2018 09:04:43 -0500
Subject: [PATCH] Fix collision panic in DeletableBloomFilter

---
 deletable.go      | 2 +-
 deletable_test.go | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/deletable.go b/deletable.go
index 2e9e810..c098d7d 100644
--- a/deletable.go
+++ b/deletable.go
@@ -42,7 +42,7 @@ func NewDeletableBloomFilter(n, r uint, fpRate float64) *DeletableBloomFilter {
 	)
 	return &DeletableBloomFilter{
 		buckets:     NewBuckets(m-r, 1),
-		collisions:  NewBuckets(r, 1),
+		collisions:  NewBuckets(r+1, 1),
 		hash:        fnv.New64(),
 		m:           m - r,
 		regionSize:  (m - r) / r,
diff --git a/deletable_test.go b/deletable_test.go
index f64859b..a5aab99 100644
--- a/deletable_test.go
+++ b/deletable_test.go
@@ -92,6 +92,14 @@ func TestDeletableTestAndAdd(t *testing.T) {
 	}
 }
 
+// Ensures collisions do not cause a panic due to regionSize.
+func TestDeletableCollisions(t *testing.T) {
+	d := NewDeletableBloomFilter(100, 120, 0.05)
+	for i := 0; i < 100; i++ {
+		d.Add([]byte(strconv.Itoa(i)))
+	}
+}
+
 // Ensures that TestAndRemove behaves correctly.
 func TestDeletableTestAndRemove(t *testing.T) {
 	d := NewDeletableBloomFilter(100, 10, 0.1)