From ebb5951693129a9757af86ff0ff4382cb0d19331 Mon Sep 17 00:00:00 2001
From: yuluo-yx <yuluo08290126@gmail.com>
Date: Sat, 8 Aug 2026 14:34:29 +0800
Subject: [PATCH] [ISSUE #10831] fix(store): handle minimum hash index in
 compaction offset map

---
 .../rocketmq/store/kv/CompactionLog.java      |  2 +-
 .../rocketmq/store/kv/OffsetMapTest.java      | 49 ++++++++++++++++++-
 2 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/store/src/main/java/org/apache/rocketmq/store/kv/CompactionLog.java b/store/src/main/java/org/apache/rocketmq/store/kv/CompactionLog.java
index be2bb551ad7..7e772144c02 100644
--- a/store/src/main/java/org/apache/rocketmq/store/kv/CompactionLog.java
+++ b/store/src/main/java/org/apache/rocketmq/store/kv/CompactionLog.java
@@ -965,7 +965,7 @@ private boolean isEmpty(int pos) {
 
         private int indexOf(byte[] hash, int tryNum) {
             int index = readInt(hash, Math.min(tryNum, hashSize - 4)) + Math.max(0, tryNum - hashSize + 4);
-            int entry = Math.abs(index) % capacity;
+            int entry = Math.floorMod(index, capacity);
             return entry * entrySize;
         }
 
diff --git a/store/src/test/java/org/apache/rocketmq/store/kv/OffsetMapTest.java b/store/src/test/java/org/apache/rocketmq/store/kv/OffsetMapTest.java
index e520c6a3bb4..38fcecc5ffc 100644
--- a/store/src/test/java/org/apache/rocketmq/store/kv/OffsetMapTest.java
+++ b/store/src/test/java/org/apache/rocketmq/store/kv/OffsetMapTest.java
@@ -16,6 +16,7 @@
  */
 package org.apache.rocketmq.store.kv;
 
+import java.security.MessageDigest;
 import org.apache.rocketmq.store.kv.CompactionLog.OffsetMap;
 import org.junit.Test;
 
@@ -50,4 +51,50 @@ public void testFull() throws Exception {
         assertEquals(offsetMap.getLastOffset(), 99);
         assertThrows(IllegalArgumentException.class, () -> offsetMap.put(String.valueOf(100), 100));
     }
-}
\ No newline at end of file
+
+    @Test
+    public void testMinimumHashValue() throws Exception {
+        OffsetMap offsetMap = new OffsetMap(0, new MinimumHashDigest());
+
+        offsetMap.put("key", 7);
+
+        assertEquals(7, offsetMap.get("key"));
+    }
+
+    private static class MinimumHashDigest extends MessageDigest {
+        private MinimumHashDigest() {
+            super("minimum-hash");
+        }
+
+        @Override
+        protected int engineGetDigestLength() {
+            return 16;
+        }
+
+        @Override
+        protected void engineUpdate(byte input) {
+        }
+
+        @Override
+        protected void engineUpdate(byte[] input, int offset, int len) {
+        }
+
+        @Override
+        protected byte[] engineDigest() {
+            byte[] digest = new byte[16];
+            digest[0] = Byte.MIN_VALUE;
+            return digest;
+        }
+
+        @Override
+        protected int engineDigest(byte[] buf, int offset, int len) {
+            byte[] digest = engineDigest();
+            System.arraycopy(digest, 0, buf, offset, digest.length);
+            return digest.length;
+        }
+
+        @Override
+        protected void engineReset() {
+        }
+    }
+}