From 0a3836a882078070451b1d17e1e08fcc45ff1dd0 Mon Sep 17 00:00:00 2001
From: Chuck Hays <haysc@webrtc.org>
Date: Tue, 21 Dec 2021 14:24:46 -0600
Subject: [PATCH] Add missing respondsToSelector call for new optional delegate
 method.

Without checking respondsToSelector, clients that don't implement the
optional delegate method will crash.

Bug: webrtc:13446
Change-Id: I3b06b15e818ca80e6afae9491c30f38c6b262eb2
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/242600
Reviewed-by: Henrik Andreassson <henrika@webrtc.org>
Auto-Submit: Chuck Hays <haysc@webrtc.org>
Commit-Queue: Chuck Hays <haysc@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#35573}
---
 sdk/objc/api/peerconnection/RTCPeerConnection.mm | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/sdk/objc/api/peerconnection/RTCPeerConnection.mm b/sdk/objc/api/peerconnection/RTCPeerConnection.mm
index 24242acadd..71ca10051e 100644
--- a/sdk/objc/api/peerconnection/RTCPeerConnection.mm
+++ b/sdk/objc/api/peerconnection/RTCPeerConnection.mm
@@ -239,7 +239,10 @@ void PeerConnectionDelegateAdapter::OnIceCandidateError(const std::string &addre
                                                                     url:url
                                                               errorCode:error_code
                                                               errorText:error_text];
-  [peer_connection.delegate peerConnection:peer_connection didFailToGatherIceCandidate:event];
+  if ([peer_connection.delegate respondsToSelector:@selector(peerConnection:
+                                                             didFailToGatherIceCandidate:)]) {
+    [peer_connection.delegate peerConnection:peer_connection didFailToGatherIceCandidate:event];
+  }
 }
 
 void PeerConnectionDelegateAdapter::OnIceCandidatesRemoved(