We saw a case where the recovery stats reported `recovered_bytes` greater than `length_in_bytes` for one file:

```
GET /_recovery?detailed

200 OK
...
{
  "name": "_buk.fdt",
  "length_in_bytes": 26891307173,
  "reused": false,
  "recovered_in_bytes": 35324928266,
  "recovered_from_snapshot_in_bytes": 8433621093
}
...
```

NB `35324928266 == 26891307173 + 8433621093`

This causes Elasticsearch to compute a negative value for the reserved space on the target node of this recovery, which prevents stats APIs from working. This appears to be caused by a network-level failure which triggers a retry without first cancelling an ongoing download of a different file with the same name from the snapshot repository.

---

### Workaround

Restart the target node to clear these stats.
server/src/main/java/org/elasticsearch/index/shard/IndexShard.java
if (state != IndexShardState.RECOVERING) {
            throw new IndexShardNotRecoveringException(shardId, state);
        }
        final EngineConfig config = newEngineConfig(globalCheckpointSupplier);
        
        
        config.setEnableGcDeletes(false);
        updateRetentionLeasesOnReplica(loadRetentionLeases());
        assert recoveryState.getRecoverySource().expectEmptyRetentionLeases() == false || getRetentionLeases().leases().isEmpty()
            : "expected empty set of retention leases with recovery source ["
                + recoveryState.getRecoverySource()
                + "] but got "
                + getRetentionLeases();
        synchronized (engineMutex) {
            assert currentEngineReference.get() == null : "engine is running";
            verifyNotClosed();
            
            final Engine newEngine = engineFactory.newReadWriteEngine(config);
            onNewEngine(newEngine);
            currentEngineReference.set(newEngine);
            
            
            active.set(true);
        }
        
        
        onSettingsChanged();
        assert assertSequenceNumbersInCommit();
        recoveryState.validateCurrentStage(RecoveryState.Stage.TRANSLOG);
    }