f Add details to register_output docs.

Author: tnull

lightning/src/chain/mod.rs

@@ -332,6 +332,10 @@ pub trait Filter {
 	fn register_tx(&self, txid: &Txid, script_pubkey: &Script);
 
 	/// Registers interest in spends of a transaction output.
+	///
+	/// Note that this method might be called during processing of a new block. You therefore need
+	/// to ensure that also dependent output spents within a block are correctly handled, e.g., by
+	/// re-scanning the block in question whenever new outputs have been registered mid-processing.
 	fn register_output(&self, output: WatchedOutput);
 }