From 8deaef670285a39f95e3798ca0db66ca7988c4e9 Mon Sep 17 00:00:00 2001
From: Amir Livneh <alivneh@fb.com>
Date: Sun, 21 Apr 2019 08:30:39 -0400
Subject: [PATCH] Fix race condition in RecordingHostnameVerifier

When connections are established concurrently, verify() sometimes throws a `java.lang.ArrayIndexOutOfBoundsException: Index 1 out of bounds for length 0` because of unsynchronized access to the `calls` list.
---
 .../src/main/java/okhttp3/RecordingHostnameVerifier.java        | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/okhttp-testing-support/src/main/java/okhttp3/RecordingHostnameVerifier.java b/okhttp-testing-support/src/main/java/okhttp3/RecordingHostnameVerifier.java
index 0b883ee02..7bae3ccac 100644
--- a/okhttp-testing-support/src/main/java/okhttp3/RecordingHostnameVerifier.java
+++ b/okhttp-testing-support/src/main/java/okhttp3/RecordingHostnameVerifier.java
@@ -24,7 +24,7 @@ public final class RecordingHostnameVerifier implements HostnameVerifier {
   public final List<String> calls = new ArrayList<>();
 
   @Override
-  public boolean verify(String hostname, SSLSession session) {
+  public synchronized boolean verify(String hostname, SSLSession session) {
     calls.add("verify " + hostname);
     return true;
   }