From 4ace3ac8634d0279e8576c1b22db5531338e9b97 Mon Sep 17 00:00:00 2001
From: Hugo Tunius <h@tunius.se>
Date: Thu, 24 Oct 2024 10:51:39 +0100
Subject: [PATCH 1/2] Fix remote candidate de-duplication

When considering whether to de-duplicate a remote candidate it's
sufficient to verify that it exists in any pair. In particular, checking
`state == CheckState::Succeeded` is problematic because in ICE lite this
is never true(ICE lite agents don't send binding requests).
---
 src/ice/agent.rs | 24 ++++++++++--------------
 1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/src/ice/agent.rs b/src/ice/agent.rs
index 8359ac35..6c8be4bd 100644
--- a/src/ice/agent.rs
+++ b/src/ice/agent.rs
@@ -383,22 +383,18 @@ impl IceAgent {
     }
 
     /// Determine whether an equivalent remote candidate is part of a viable candidate pair.
-    pub fn find_viable_pair_for_equivalent_remote_candidate(
+    pub fn find_pair_for_equivalent_remote_candidate(
         &self,
         c: &Candidate,
     ) -> Option<&CandidatePair> {
-        self.candidate_pairs
-            .iter()
-            .filter(|cand| cand.state() == CheckState::Succeeded)
-            .find(|pair| {
-                let o = &self.remote_candidates[pair.remote_idx()];
-
-                c.addr() == o.addr()
-                    && c.base() == o.base()
-                    && c.proto() == o.proto()
-                    && c.kind() == o.kind()
-                    && c.raddr() == o.raddr()
-            })
+        self.candidate_pairs.iter().find(|pair| {
+            let o = &self.remote_candidates[pair.remote_idx()];
+            c.addr() == o.addr()
+                && c.base() == o.base()
+                && c.proto() == o.proto()
+                && c.kind() == o.kind()
+                && c.raddr() == o.raddr()
+        })
     }
 
     /// Credentials for STUN.
@@ -642,7 +638,7 @@ impl IceAgent {
         // confusing inspecting the state.
         c.clear_ufrag();
 
-        let existing_pair = self.find_viable_pair_for_equivalent_remote_candidate(&c);
+        let existing_pair = self.find_pair_for_equivalent_remote_candidate(&c);
         let existing_candidate =
             existing_pair.map(|p| (p.remote_idx(), &self.remote_candidates[p.remote_idx()]));
 

From 135da62762a562984963270b04a1c0a010be3f6b Mon Sep 17 00:00:00 2001
From: Hugo Tunius <h@tunius.se>
Date: Thu, 24 Oct 2024 10:57:13 +0100
Subject: [PATCH 2/2] Tweak log and copy order

---
 src/ice/agent.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/ice/agent.rs b/src/ice/agent.rs
index 6c8be4bd..1e8ba515 100644
--- a/src/ice/agent.rs
+++ b/src/ice/agent.rs
@@ -748,13 +748,13 @@ impl IceAgent {
                             );
                         } else {
                             // replace the existing candidate pair, since the new one got a higher prio.
+                            pair.copy_nominated_and_success_state(&self.candidate_pairs[check_idx]);
+
                             debug!(
                                 "Replace redundant pair, current: {:?} replaced with: {:?}",
                                 check, pair
                             );
 
-                            pair.copy_nominated_and_success_state(&self.candidate_pairs[check_idx]);
-
                             if self.ice_lite {
                                 debug!("Retain incoming binding requests for pair");
                                 pair.copy_remote_binding_requests(&self.candidate_pairs[check_idx]);