fix vsf bug when restoring entries on a failed reclaim

indexing-service/src/test/java/org/apache/druid/indexing/seekablestream/supervisor/SeekableStreamSupervisorSpecTest.java

@@ -1155,7 +1155,7 @@ public String getSource()
       }
     };
 
-    // Mistmatched stream strings test
+    // Mismatched stream strings test
     MatcherAssert.assertThat(
         assertThrows(DruidException.class, () -> originalSpec.validateSpecUpdateTo(proposedSpecDiffSource)),
         new DruidExceptionMatcher(

server/src/main/java/org/apache/druid/segment/loading/StorageLocation.java

@@ -779,7 +779,7 @@ private ReclaimResult reclaimHelper(long sizeToReclaim, List<WeakCacheEntry> dro
     }
     // if we didn't free up enough space, return everything we removed to the cache
     for (WeakCacheEntry entry : droppedEntries) {
-      linkNewWeakEntry(new WeakCacheEntry(entry.cacheEntry));
+      linkNewWeakEntry(entry);
       weakCacheEntries.put(entry.cacheEntry.getId(), entry);
     }
     return ReclaimResult.failed(sizeToReclaim);

server/src/test/java/org/apache/druid/segment/loading/StorageLocationTest.java

@@ -369,6 +369,33 @@ public void testReserveWeakExistsConcurrency() throws ExecutionException, Interr
     Assertions.assertEquals(0, loc.getActiveWeakHolds());
   }
 
+  @Test
+  public void testReclaimRestoreDoesNotCreateZombieEntries()
+  {
+    StorageLocation location = new StorageLocation(tempDir, 100L, null);
+    CacheEntry entry1 = new TestCacheEntry("1", 10);
+    CacheEntry entry2 = new TestCacheEntry("2", 90);
+    CacheEntry entry3 = new TestCacheEntry("3", 20);
+
+    location.reserveWeak(entry1);
+    // hold entry2 so it cannot be evicted by reclaim
+    StorageLocation.ReservationHold<?> hold2 = location.addWeakReservationHold(
+        entry2.getId(),
+        () -> entry2
+    );
+
+    // must free 20 bytes but can only evict entry1 (10). Fails and restores entry1
+    // where the bug was a mismatch caused by creating a new entry in the list but re-using the old entry for the map.
+    Assertions.assertFalse(location.reserveWeak(entry3));
+
+    // the hand pointer reaches the new entry1, removes the old entry1 from the map which is a zombie, then wraps around
+    // to the same zombie entry1 again since its head — at which point the map no longer contains the ID and the defensive exception was
+    // thrown.
+    Assertions.assertFalse(location.reserveWeak(entry3));
+
+    hold2.close();
+  }
+
   @SuppressWarnings({"GuardedBy", "FieldAccessNotGuarded"})
   private void verifyLoc(long maxSize, StorageLocation loc)
   {