pulsar/0017-return-earliest-position.patch

diff --git a/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/ManagedCursor.java b/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/ManagedCursor.java
index 46ca0f1400..0653e40cb3 100644
--- a/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/ManagedCursor.java
+++ b/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/ManagedCursor.java
@@ -532,6 +532,23 @@ public interface ManagedCursor {
     void asyncFindNewestMatching(FindPositionConstraint constraint, Predicate<Entry> condition,
             FindEntryCallback callback, Object ctx);
 
+    /**
+     * Find the newest entry that matches the given predicate.
+     *
+     * @param constraint
+     *            search only active entries or all entries
+     * @param condition
+     *            predicate that reads an entry an applies a condition
+     * @param callback
+     *            callback object returning the resultant position
+     * @param ctx
+     *            opaque context
+     * @param isFindFromLedger
+     *            find the newest entry from ledger
+     */
+    void asyncFindNewestMatching(FindPositionConstraint constraint, Predicate<Entry> condition,
+            FindEntryCallback callback, Object ctx, boolean isFindFromLedger);
+
     /**
      * reset the cursor to specified position to enable replay of messages.
      *
diff --git a/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/ManagedCursorImpl.java b/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/ManagedCursorImpl.java
index 011d3df77f..6045412398 100644
--- a/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/ManagedCursorImpl.java
+++ b/managed-ledger/src/main/java/org/apache/bookkeeper/mledger/impl/ManagedCursorImpl.java
@@ -1078,6 +1078,12 @@ public class ManagedCursorImpl implements ManagedCursor {
     @Override
     public void asyncFindNewestMatching(FindPositionConstraint constraint, Predicate<Entry> condition,
             FindEntryCallback callback, Object ctx) {
+        asyncFindNewestMatching(constraint, condition, callback, ctx, false);
+    }
+
+    @Override
+    public void asyncFindNewestMatching(FindPositionConstraint constraint, Predicate<Entry> condition,
+            FindEntryCallback callback, Object ctx, boolean isFindFromLedger) {
         OpFindNewest op;
         PositionImpl startPosition = null;
         long max = 0;
@@ -1099,7 +1105,11 @@ public class ManagedCursorImpl implements ManagedCursor {
                     Optional.empty(), ctx);
             return;
         }
-        op = new OpFindNewest(this, startPosition, condition, max, callback, ctx);
+        if (isFindFromLedger) {
+            op = new OpFindNewest(this.ledger, startPosition, condition, max, callback, ctx);
+        } else {
+            op = new OpFindNewest(this, startPosition, condition, max, callback, ctx);
+        }
         op.find();
     }
 
diff --git a/managed-ledger/src/test/java/org/apache/bookkeeper/mledger/impl/ManagedCursorContainerTest.java b/managed-ledger/src/test/java/org/apache/bookkeeper/mledger/impl/ManagedCursorContainerTest.java
index 18fe4dba31..675f28e2d2 100644
--- a/managed-ledger/src/test/java/org/apache/bookkeeper/mledger/impl/ManagedCursorContainerTest.java
+++ b/managed-ledger/src/test/java/org/apache/bookkeeper/mledger/impl/ManagedCursorContainerTest.java
@@ -241,6 +241,11 @@ public class ManagedCursorContainerTest {
                 AsyncCallbacks.FindEntryCallback callback, Object ctx) {
         }
 
+        @Override
+        public void asyncFindNewestMatching(FindPositionConstraint constraint, Predicate<Entry> condition,
+                AsyncCallbacks.FindEntryCallback callback, Object ctx, boolean isFindFromLedger) {
+        }
+
         @Override
         public void asyncResetCursor(final Position position, boolean forceReset,
                 AsyncCallbacks.ResetCursorCallback callback) {
diff --git a/pulsar-broker/src/main/java/org/apache/pulsar/broker/service/persistent/PersistentMessageFinder.java b/pulsar-broker/src/main/java/org/apache/pulsar/broker/service/persistent/PersistentMessageFinder.java
index 825bc546f4..838771e6d3 100644
--- a/pulsar-broker/src/main/java/org/apache/pulsar/broker/service/persistent/PersistentMessageFinder.java
+++ b/pulsar-broker/src/main/java/org/apache/pulsar/broker/service/persistent/PersistentMessageFinder.java
@@ -71,7 +71,7 @@ public class PersistentMessageFinder implements AsyncCallbacks.FindEntryCallback
                     entry.release();
                 }
                 return false;
-            }, this, callback);
+            }, this, callback, true);
         } else {
             if (log.isDebugEnabled()) {
                 log.debug("[{}][{}] Ignore message position find scheduled task, last find is still running", topicName,
diff --git a/pulsar-broker/src/test/java/org/apache/pulsar/broker/service/PersistentMessageFinderTest.java b/pulsar-broker/src/test/java/org/apache/pulsar/broker/service/PersistentMessageFinderTest.java
index e70d0dc2b5..da78a0411d 100644
--- a/pulsar-broker/src/test/java/org/apache/pulsar/broker/service/PersistentMessageFinderTest.java
+++ b/pulsar-broker/src/test/java/org/apache/pulsar/broker/service/PersistentMessageFinderTest.java
@@ -243,6 +243,40 @@ public class PersistentMessageFinderTest extends MockedBookKeeperTestCase {
         factory.shutdown();
     }
 
+    @Test
+    void testPersistentMessageFinderWhenLastMessageDelete() throws Exception {
+        final String ledgerAndCursorName = "testPersistentMessageFinderWhenLastMessageDelete";
+
+        ManagedLedgerConfig config = new ManagedLedgerConfig();
+        config.setRetentionSizeInMB(10);
+        config.setMaxEntriesPerLedger(10);
+        config.setRetentionTime(1, TimeUnit.HOURS);
+        ManagedLedger ledger = factory.open(ledgerAndCursorName, config);
+        ManagedCursorImpl cursor = (ManagedCursorImpl) ledger.openCursor(ledgerAndCursorName);
+
+        ledger.addEntry(createMessageWrittenToLedger("msg1"));
+        ledger.addEntry(createMessageWrittenToLedger("msg2"));
+        ledger.addEntry(createMessageWrittenToLedger("msg3"));
+        Position lastPosition = ledger.addEntry(createMessageWrittenToLedger("last-message"));
+
+        long endTimestamp = System.currentTimeMillis() + 1000;
+
+        Result result = new Result();
+        // delete last position message
+        cursor.delete(lastPosition);
+        CompletableFuture<Void> future = findMessage(result, cursor, endTimestamp);
+        future.get();
+        assertNull(result.exception);
+        assertNotEquals(result.position, null);
+        assertEquals(result.position, lastPosition);
+
+        result.reset();
+        cursor.close();
+        ledger.close();
+        factory.shutdown();
+    }
+
+
     @Test
     void testPersistentMessageFinderWithBrokerTimestampForMessage() throws Exception {