changes in goLevelDBIterator Value() impl:

- returns the value itself, not a copy
- updated tests to reflect the change
- updated docs to reflect the change

backend_test.go

@@ -451,7 +451,10 @@ func assertKeyValues(t *testing.T, db DB, expect map[string][]byte) {
 	actual := make(map[string][]byte)
 	for ; iter.Valid(); iter.Next() {
 		require.NoError(t, iter.Error())
-		actual[string(iter.Key())] = iter.Value()
+
+		value := make([]byte, len(iter.Value()))
+		copy(value, iter.Value())
+		actual[string(iter.Key())] = value
 	}
 
 	assert.Equal(t, expect, actual)

common_test.go

@@ -72,7 +72,9 @@ func checkKeyPanics(t *testing.T, itr Iterator) {
 
 func checkValuePanics(t *testing.T, itr Iterator) {
 	t.Helper()
-	assert.Panics(t, func() { itr.Value() })
+
+	msg := "checkValuePanics expected panic but didn't"
+	assert.Panics(t, func() { itr.Value() }, msg)
 }
 
 func newTempDB(t *testing.T, backend BackendType) (db DB, dbDir string) {

goleveldb_iterator.go

@@ -94,18 +94,18 @@ func (itr *goLevelDBIterator) Valid() bool {
 
 // Key implements Iterator.
 // The caller should not modify the contents of the returned slice.
-// To work with the slice, make a copy and modify the copy instead.
+// Instead, the caller should make a copy and work on the copy.
 func (itr *goLevelDBIterator) Key() []byte {
 	itr.assertIsValid()
 	return itr.source.Key()
 }
 
 // Value implements Iterator.
+// The caller should not modify the contents of the returned slice.
+// Instead, the caller should make a copy and work on the copy.
 func (itr *goLevelDBIterator) Value() []byte {
-	// Value returns a copy of the current value.
-	// See https://github.com/syndtr/goleveldb/blob/52c212e6c196a1404ea59592d3f1c227c9f034b2/leveldb/iterator/iter.go#L88
 	itr.assertIsValid()
-	return cp(itr.source.Value())
+	return itr.source.Value()
 }
 
 // Next implements Iterator.