From bf5a8499b8b624adee91ec1970cb402f22f79cf8 Mon Sep 17 00:00:00 2001
From: Chris Larsen <clarsen@netflix.com>
Date: Thu, 12 Sep 2024 21:19:21 -0700
Subject: [PATCH] ipc: Fix NPE from #1150 if IPC logger is not configured.
 (#1157)

Results in a
`java.lang.NullPointerException: Cannot invoke "com.netflix.spectator.ipc.IpcLogger.inflightEnabled()" because "this.logger" is null`
---
 .../java/com/netflix/spectator/ipc/IpcLogEntry.java   |  2 +-
 .../com/netflix/spectator/ipc/IpcLogEntryTest.java    | 11 +++++++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/spectator-ext-ipc/src/main/java/com/netflix/spectator/ipc/IpcLogEntry.java b/spectator-ext-ipc/src/main/java/com/netflix/spectator/ipc/IpcLogEntry.java
index 2f843b6e6..bf7009e4d 100644
--- a/spectator-ext-ipc/src/main/java/com/netflix/spectator/ipc/IpcLogEntry.java
+++ b/spectator-ext-ipc/src/main/java/com/netflix/spectator/ipc/IpcLogEntry.java
@@ -156,7 +156,7 @@ public IpcLogEntry withLatency(long latency, TimeUnit unit) {
    * the request completes it is recommended to call {@link #markEnd()}.
    */
   public IpcLogEntry markStart() {
-    if (registry != null && !disableMetrics && logger.inflightEnabled()) {
+    if (registry != null && !disableMetrics && logger != null && logger.inflightEnabled()) {
       inflightId = getInflightId();
       int n = logger.inflightRequests(inflightId).incrementAndGet();
       registry.distributionSummary(inflightId).record(n);
diff --git a/spectator-ext-ipc/src/test/java/com/netflix/spectator/ipc/IpcLogEntryTest.java b/spectator-ext-ipc/src/test/java/com/netflix/spectator/ipc/IpcLogEntryTest.java
index 526e05356..8e7336e4e 100644
--- a/spectator-ext-ipc/src/test/java/com/netflix/spectator/ipc/IpcLogEntryTest.java
+++ b/spectator-ext-ipc/src/test/java/com/netflix/spectator/ipc/IpcLogEntryTest.java
@@ -20,6 +20,7 @@
 import com.netflix.spectator.api.DefaultRegistry;
 import com.netflix.spectator.api.DistributionSummary;
 import com.netflix.spectator.api.ManualClock;
+import com.netflix.spectator.api.NoopRegistry;
 import com.netflix.spectator.api.Registry;
 import com.netflix.spectator.api.Utils;
 import com.netflix.spectator.api.patterns.CardinalityLimiters;
@@ -36,6 +37,8 @@
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 
+import static org.junit.jupiter.api.Assertions.assertSame;
+
 public class IpcLogEntryTest {
 
   private final ManualClock clock = new ManualClock();
@@ -889,4 +892,12 @@ public void endpointUnknownIfNotSet() {
       Assertions.assertEquals("unknown", Utils.getTagValue(c.id(), "ipc.endpoint"));
     });
   }
+
+  @Test
+  public void markNullLogger() {
+    IpcLogEntry entry = new IpcLogEntry(clock)
+        .withRegistry(new NoopRegistry());
+    entry.markStart();
+    assertSame(entry, entry.markEnd());
+  }
 }