fix[kad]: enable putting Record with None publisher in a confusing way. Sorry for that, see <libp2p#6176 (comment)> for some details.

Author: skaunov

protocols/kad/CHANGELOG.md

@@ -1,3 +1,5 @@
+- minimized #6176
+
 ## 0.49.0
 
 - Remove no longer constructed GetRecordError::QuorumFailed.

protocols/kad/src/behaviour.rs

@@ -870,7 +870,9 @@ where
         mut record: Record,
         quorum: Quorum,
     ) -> Result<QueryId, store::Error> {
-        record.publisher = Some(*self.kbuckets.local_key().preimage());
+        if record.publisher.is_some() {
+            record.publisher = Some(*self.kbuckets.local_key().preimage())
+        }
         self.store.put(record.clone())?;
         record.expires = record
             .expires

protocols/kad/src/behaviour/test.rs

@@ -562,7 +562,11 @@ fn get_record_not_found() {
 /// is equal to the configured replication factor.
 #[test]
 fn put_record() {
-    fn prop(records: Vec<Record>, seed: Seed, filter_records: bool, drop_records: bool) {
+    fn prop(mut records: Vec<Record>, seed: Seed, filter_records: bool, drop_records: bool) {
+        tracing::trace!("remove records without a publisher");
+        // this test relies on counting republished `Record` against `records.len()`
+        records.retain(|r| r.publisher.is_some());
+        
         let mut rng = StdRng::from_seed(seed.0);
         let replication_factor =
             NonZeroUsize::new(rng.gen_range(1..(K_VALUE.get() / 2) + 1)).unwrap();

protocols/kad/src/record.rs

@@ -94,6 +94,16 @@ impl Record {
     where
         K: Into<Key>,
     {
+        Record {
+            key: key.into(),
+            value,
+            publisher: Some(PeerId::random()),
+            expires: None,
+        }
+    }
+
+    /// Creates a new record for insertion into the DHT.
+    pub fn new_anonymous(key: impl Into<Key>, value: Vec<u8>) -> Self {
         Record {
             key: key.into(),
             value,