Transfer: avoid checksum-path crash when JFR message source is unresolved

modules/dcache/src/main/java/org/dcache/util/Transfer.java

@@ -618,6 +618,11 @@ public synchronized String getDomainName() {
         return _cellAddress.getCellDomainName();
     }
 
+    private synchronized String getMessageEventSource() {
+        return _cellAddress == null ? "<unknown>" :
+              _cellAddress.getCellName() + "@" + _cellAddress.getCellDomainName();
+    }
+
     /**
      * The client address is the socket address from which the transfer was initiated.
      */
@@ -821,7 +826,7 @@ private ListenableFuture<Void> readNameSpaceEntryAsync(boolean allowWrite, long
         request.setUpdateAtime(true);
 
         MessageEvent nameSpaceReadEvent = new MessageEvent();
-        nameSpaceReadEvent.source = getCellName() + "@" + getDomainName();
+        nameSpaceReadEvent.source = getMessageEventSource();
         nameSpaceReadEvent.destination = "PnfsManager";
         nameSpaceReadEvent.message = PnfsGetFileAttributes.class.getSimpleName();
         nameSpaceReadEvent.begin();
@@ -996,7 +1001,7 @@ public ListenableFuture<Void> selectPoolAsync(long timeout) {
 
         // init JFR event
         MessageEvent poolSelectEvent = new MessageEvent();
-        poolSelectEvent.source = getCellName() + "@" + getDomainName();
+        poolSelectEvent.source = getMessageEventSource();
         poolSelectEvent.destination = "PoolManager";
         poolSelectEvent.message = isWrite() ? PoolMgrSelectReadPoolMsg.class.getSimpleName() : PoolMgrSelectWritePoolMsg.class.getSimpleName();
         poolSelectEvent.begin();
@@ -1102,7 +1107,7 @@ public ListenableFuture<Void> startMoverAsync(long timeout) {
 
         // init JFR event
         MessageEvent moverStartEvent = new MessageEvent();
-        moverStartEvent.source = getCellName() + "@" + getDomainName();
+        moverStartEvent.source = getMessageEventSource();
         moverStartEvent.destination = pool.getName();
         moverStartEvent.message = message.getClass().getSimpleName();
         moverStartEvent.begin();
@@ -1169,7 +1174,7 @@ public void killMover(long millis, String explanation) {
 
             // init JFR event
             var killMoverEvent = new MessageEvent();
-            killMoverEvent.source = getCellName() + "@" + getDomainName();
+            killMoverEvent.source = getMessageEventSource();
             killMoverEvent.destination = pool.getName();
             killMoverEvent.message = message.getClass().getSimpleName();
 

modules/dcache/src/test/java/org/dcache/util/TransferTest.java

@@ -0,0 +1,64 @@
+/* dCache - http://www.dcache.org/
+ *
+ * Copyright (C) 2026 Deutsches Elektronen-Synchrotron
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.dcache.util;
+
+import static com.google.common.util.concurrent.Futures.immediateFuture;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyLong;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import diskCacheV111.util.FsPath;
+import diskCacheV111.util.PnfsHandler;
+import diskCacheV111.vehicles.GenericStorageInfo;
+import javax.security.auth.Subject;
+import org.dcache.auth.attributes.Restrictions;
+import org.dcache.cells.CellStub;
+import org.dcache.namespace.FileType;
+import org.dcache.vehicles.FileAttributes;
+import org.dcache.vehicles.PnfsGetFileAttributes;
+import org.junit.Test;
+
+public class TransferTest {
+
+    @Test
+    public void shouldReadNamespaceEntryWithoutCellAddress() throws Exception {
+        CellStub stub = mock(CellStub.class);
+        when(stub.send(any(PnfsGetFileAttributes.class), anyLong())).thenAnswer(invocation -> {
+            PnfsGetFileAttributes request = invocation.getArgument(0);
+            PnfsGetFileAttributes reply =
+                  new PnfsGetFileAttributes(request.getPnfsPath(),
+                        request.getRequestedAttributes());
+            FileAttributes attributes = FileAttributes.of()
+                  .fileType(FileType.REGULAR)
+                  .size(1L)
+                  .storageInfo(new GenericStorageInfo())
+                  .build();
+            reply.setFileAttributes(attributes);
+            return immediateFuture(reply);
+        });
+
+        Transfer transfer = new Transfer(new PnfsHandler(stub), new Subject(),
+              Restrictions.none(), FsPath.create("/test/path"));
+
+        transfer.readNameSpaceEntry(false);
+
+        verify(stub).send(any(PnfsGetFileAttributes.class), anyLong());
+    }
+}