From c82e4563c2c0a3c97b0d02749e31e4b391a08762 Mon Sep 17 00:00:00 2001
From: Shichao Nie <niesc@automq.com>
Date: Thu, 2 Nov 2023 19:01:31 +0800
Subject: [PATCH] fix(s3stream): fix potential NPE in compaction (#552)

Signed-off-by: Shichao Nie <niesc@automq.com>
---
 .../java/com/automq/stream/s3/compact/CompactionManager.java | 5 +++--
 .../java/com/automq/stream/s3/compact/CompactionUtils.java   | 4 +++-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/s3stream/src/main/java/com/automq/stream/s3/compact/CompactionManager.java b/s3stream/src/main/java/com/automq/stream/s3/compact/CompactionManager.java
index 1a6099358..eda57e243 100644
--- a/s3stream/src/main/java/com/automq/stream/s3/compact/CompactionManager.java
+++ b/s3stream/src/main/java/com/automq/stream/s3/compact/CompactionManager.java
@@ -233,8 +233,9 @@ private void logCompactionPlans(List<CompactionPlan> compactionPlans, Set<Long>
                         .mapToLong(CompactedObject::size)
                         .sum())
                 .sum();
-        logger.info("Compaction plans: expect to generate {} StreamObject, 1 WAL object with size {} in {} iterations, objects excluded: {}",
-                streamObjectNum, walObjectSize, compactionPlans.size(), excludedObjectIds);
+        int walObjectNum = walObjectSize > 0 ? 1 : 0;
+        logger.info("Compaction plans: expect to generate {} Stream Object, {} WAL object with size {} in {} iterations, objects excluded: {}",
+                streamObjectNum, walObjectNum, walObjectSize, compactionPlans.size(), excludedObjectIds);
     }
 
     public CompletableFuture<Void> forceSplitAll() {
diff --git a/s3stream/src/main/java/com/automq/stream/s3/compact/CompactionUtils.java b/s3stream/src/main/java/com/automq/stream/s3/compact/CompactionUtils.java
index 8c04c096b..bb3b544b9 100644
--- a/s3stream/src/main/java/com/automq/stream/s3/compact/CompactionUtils.java
+++ b/s3stream/src/main/java/com/automq/stream/s3/compact/CompactionUtils.java
@@ -52,7 +52,9 @@ public static List<ObjectStreamRange> buildObjectStreamRange(List<StreamDataBloc
                 }
             }
         }
-        objectStreamRanges.add(currObjectStreamRange);
+        if (currObjectStreamRange != null) {
+            objectStreamRanges.add(currObjectStreamRange);
+        }
         return objectStreamRanges;
     }