libp2p: revise published address count/selection

1 files changed, 17 insertions, 4 deletions

diff --git a/src/transport/paths.rs b/src/transport/paths.rs
index 658f681..ce19fd4 100644
--- a/src/transport/paths.rs
+++ b/src/transport/paths.rs
@@ -620,17 +620,30 @@ impl Paths {
             .unwrap_or_default()
     }
 
-    /// Each transport's (`Transport::local_addresses`), with its scheme.
+    /// Each transport's (`Transport::local_addresses`), with its scheme: taken in turns,
+    /// each transport's first in the configured order, then each one's second, and so on,
+    /// so a list cut short (`members::MAX_ADDRESSES`) still has every transport's best.
     pub(crate) fn local_addresses(&self) -> Vec<String> {
-        self.links
+        let mut each: Vec<std::vec::IntoIter<String>> = self
+            .links
             .iter()
-            .flat_map(|link| {
+            .map(|link| {
                 link.inner
                     .local_addresses()
                     .into_iter()
                     .map(|target| link.address(&target))
+                    .collect::<Vec<_>>()
+                    .into_iter()
             })
-            .collect()
+            .collect();
+        let mut addresses = Vec::new();
+        loop {
+            let before = addresses.len();
+            addresses.extend(each.iter_mut().filter_map(Iterator::next));
+            if addresses.len() == before {
+                return addresses;
+            }
+        }
     }
 
     /// The schemes of the transports, in order of preference.