Fix kill_prefix

primitives/io/src/lib.rs

@@ -1766,6 +1766,11 @@ mod tests {
 			assert!(storage::get(b":abdd").is_some());
 			assert!(storage::get(b":abcd").is_none());
 			assert!(storage::get(b":abc").is_none());
+
+			assert!(matches!(
+				storage::clear_prefix(b":abc", None),
+				KillStorageResult::AllRemoved(0)
+			));
 		});
 	}
 

primitives/state-machine/src/ext.rs

@@ -465,6 +465,7 @@ where
 
 		self.mark_dirty();
 		let _overlay_count = self.overlay.clear_prefix(prefix);
+//, Some(&self.overlay.changes)
 		let (all, count) = self.limit_remove_from_backend(None, Some(prefix), limit);
 		(all, count)
 	}
@@ -486,6 +487,7 @@ where
 
 		self.mark_dirty();
 		let _overlay_count = self.overlay.clear_child_prefix(child_info, prefix);
+//, Some(&self.overlay.changes)
 		let (all, count) = self.limit_remove_from_backend(Some(child_info), Some(prefix), limit);
 		(all, count)
 	}
@@ -743,6 +745,13 @@ where
 					all_deleted = false;
 					return false
 				}
+				if let Some(None) = match child_info {
+					Some(child_info) => self.overlay.child_storage(child_info, key),
+					None => self.overlay.storage(key),
+				} {
+					// already deleted.
+					return true;
+				}
 				if let Some(num) = num_deleted.checked_add(1) {
 					num_deleted = num;
 				} else {
@@ -759,6 +768,13 @@ where
 			(all_deleted, num_deleted)
 		} else {
 			self.backend.apply_to_keys_while(child_info, prefix, |key| {
+				if let Some(None) = match child_info {
+					Some(child_info) => self.overlay.child_storage(child_info, key),
+					None => self.overlay.storage(key),
+				} {
+					// already deleted.
+					return true;
+				}
 				num_deleted = num_deleted.saturating_add(1);
 				if let Some(child_info) = child_info {
 					self.overlay.set_child_storage(child_info, key.to_vec(), None);