Properly reset BTree iteration state on boundaries

Closes paritytech#152
Tpt · Oct 24, 2022 · 3e86952 · 3e86952
1 parent 2a11bb0
commit 3e86952
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Showing 2 changed files with 5 additions and 1 deletion.
diff --git a/src/btree/iter.rs b/src/btree/iter.rs
@@ -277,7 +277,7 @@ impl BTreeIterState {
 
 	fn exit(&mut self, direction: IterDirection) -> bool {
 		loop {
-			if self.state.len() < 2 {
+			if self.state.is_empty() {
 				return true
 			}
 			self.state.pop();

diff --git a/src/db.rs b/src/db.rs
@@ -1760,6 +1760,10 @@ mod tests {
 		iter.seek_to_first().unwrap();
 		assert_eq!(iter.next().unwrap(), Some((key1.clone(), b"value1".to_vec())));
 		assert_eq!(iter.next().unwrap(), None);
+		assert_eq!(iter.prev().unwrap(), Some((key1.clone(), b"value1".to_vec())));
+		assert_eq!(iter.prev().unwrap(), None);
+		assert_eq!(iter.next().unwrap(), Some((key1.clone(), b"value1".to_vec())));
+		assert_eq!(iter.next().unwrap(), None);
 
 		iter.seek_to_first().unwrap();
 		assert_eq!(iter.next().unwrap(), Some((key1.clone(), b"value1".to_vec())));