From 75d681a93cdcd5c6bf112c89ca1f132322c62d90 Mon Sep 17 00:00:00 2001
From: zzz <zzz@mail.i2p>
Date: Mon, 23 Apr 2018 15:48:44 +0000
Subject: [PATCH] Clock: Fix early NPE via DoH

---
 router/java/src/net/i2p/router/RouterClock.java | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/router/java/src/net/i2p/router/RouterClock.java b/router/java/src/net/i2p/router/RouterClock.java
index c4b4af066..a0932c7d0 100644
--- a/router/java/src/net/i2p/router/RouterClock.java
+++ b/router/java/src/net/i2p/router/RouterClock.java
@@ -150,7 +150,10 @@ public class RouterClock extends Clock {
                 _alreadyChanged) {
 
                 // Try calculating peer clock skew
-                long currentPeerClockSkew = ((RouterContext)_context).commSystem().getFramedAveragePeerClockSkew(33);
+                // This may get called very early at startup, before RouterContext.initAll() is completed,
+                // so the comm system may be null. Avoid NPE.
+                CommSystemFacade csf = ((RouterContext)_context).commSystem();
+                long currentPeerClockSkew = (csf != null) ? csf.getFramedAveragePeerClockSkew(33) : 0;
 
                     // Predict the effect of applying the proposed clock offset
                     long predictedPeerClockSkew = currentPeerClockSkew + delta;