From 3c6c3ac0a2ceb97115487baf586b3692550384f0 Mon Sep 17 00:00:00 2001
From: Pavel Borzenkov <pavel.borzenkov@gmail.com>
Date: Wed, 8 Feb 2017 18:24:56 +0300
Subject: [PATCH 1/2] Add a test for deletion of non-existing key

As of now the test fails and tries to delete the next key returned by
the cursor, which happens to be a nested bucket. That's why Delete is
fails.

Signed-off-by: Pavel Borzenkov <pavel.borzenkov@gmail.com>
---
 bucket_test.go | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/bucket_test.go b/bucket_test.go
index c75f71ff..6d96e662 100644
--- a/bucket_test.go
+++ b/bucket_test.go
@@ -441,6 +441,39 @@ func TestBucket_Delete_FreelistOverflow(t *testing.T) {
 	}
 }
 
+// Ensure that deleting of non-existing key is a no-op.
+func TestBucket_Delete_NonExisting(t *testing.T) {
+	db := MustOpenDB()
+	defer db.MustClose()
+
+	if err := db.Update(func(tx *bolt.Tx) error {
+		b, err := tx.CreateBucket([]byte("widgets"))
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if _, err = b.CreateBucket([]byte("nested")); err != nil {
+			t.Fatal(err)
+		}
+		return nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := db.Update(func(tx *bolt.Tx) error {
+		b := tx.Bucket([]byte("widgets"))
+		if err := b.Delete([]byte("foo")); err != nil {
+			t.Fatal(err)
+		}
+		if b.Bucket([]byte("nested")) == nil {
+			t.Fatal("nested bucket has been deleted")
+		}
+		return nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+}
+
 // Ensure that accessing and updating nested buckets is ok across transactions.
 func TestBucket_Nested(t *testing.T) {
 	db := MustOpenDB()

From 6336a429d168668797fbcb4d1f9e3895ae8aa8e2 Mon Sep 17 00:00:00 2001
From: Pavel Borzenkov <pavel.borzenkov@gmail.com>
Date: Wed, 8 Feb 2017 18:25:52 +0300
Subject: [PATCH 2/2] Fix deletion of non-existing keys

Doc for Bucket.Delete says that a Delete() on non-existing key is a
no-op. Right now it tries to delete the next key returned by the
cursor. Fix this by checking for key equivalence before deletion.

 Fixes #349

Signed-off-by: Pavel Borzenkov <pavel.borzenkov@gmail.com>
---
 bucket.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/bucket.go b/bucket.go
index 0c5bf274..93f9d951 100644
--- a/bucket.go
+++ b/bucket.go
@@ -323,7 +323,12 @@ func (b *Bucket) Delete(key []byte) error {
 
 	// Move cursor to correct position.
 	c := b.Cursor()
-	_, _, flags := c.seek(key)
+	k, _, flags := c.seek(key)
+
+	// Return nil if the key doesn't exist.
+	if !bytes.Equal(key, k) {
+		return nil
+	}
 
 	// Return an error if there is already existing bucket value.
 	if (flags & bucketLeafFlag) != 0 {