f doc msg delivery somewhat

Author: TheBlueMatt

fuzz/src/chanmon_consistency.rs

@@ -578,10 +578,20 @@ pub fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
 			} }
 		}
 
+		// While delivering messages, we select across three possible message selection processes
+		// to ensure we get as much coverage as possible. See the individual enum variants for more
+		// details.
 		#[derive(PartialEq)]
 		enum ProcessMessages {
+			/// Deliver all available messages, including fetching any new messages from
+			/// `get_and_clear_pending_msg_events()` (which may have side effects).
 			AllMessages,
+			/// Call `get_and_clear_pending_msg_events()` first, and then deliver up to one
+			/// message (which may already be queued).
 			OneMessage,
+			/// Deliver up to one already-queued message. This avoids any potential side-effects
+			/// of `get_and_clear_pending_msg_events()` (eg freeing the HTLC holding cell), which
+			/// provides potentially more coverage.
 			OnePendingMessage,
 		}