storage: fix BoltDB batched Put()

It must copy both the value and the key because they can be reused for other
purposes between Put() and PutBatch(). This actually happens with values in
headers processing, leading to wrong data being written into the DB.

Extend the batch test to check for that.

pkg/core/storage/boltdb_store.go

@@ -36,7 +36,11 @@ func (b *BoltDBBatch) Len() int {
 
 // Put implements the Batch interface.
 func (b *BoltDBBatch) Put(k, v []byte) {
-	b.mem[&k] = v
+	vcopy := make([]byte, len(v))
+	copy(vcopy, v)
+	kcopy := make([]byte, len(k))
+	copy(kcopy, k)
+	b.mem[&kcopy] = vcopy
 }
 
 // NewBoltDBStore returns a new ready to use BoltDB storage with created bucket.

pkg/core/storage/boltdb_store_test.go

@@ -26,11 +26,17 @@ func TestBoltDBBatch_Len(t *testing.T) {
 
 func TestBoltDBBatch_PutBatchAndGet(t *testing.T) {
 	key := []byte("foo")
+	keycopy := make([]byte, len(key))
+	copy(keycopy, key)
 	value := []byte("bar")
-	batch := &BoltDBBatch{mem: map[*[]byte][]byte{&key: value}}
-
+	valuecopy := make([]byte, len(value))
+	copy(valuecopy, value)
 	boltDBStore := openStore(t)
+	batch := boltDBStore.Batch()
 
+	batch.Put(keycopy, valuecopy)
+	copy(valuecopy, key)
+	copy(keycopy, value)
 	errPut := boltDBStore.PutBatch(batch)
 	assert.Nil(t, errPut, "Error while PutBatch")