Fix deleting unassigned indices in MP

server/src/main/java/org/elasticsearch/indices/IndicesService.java

@@ -1066,12 +1066,12 @@ public void afterIndexShardClosed(ShardId shardId, IndexShard indexShard, Settin
      * but does not deal with in-memory structures. For those call {@link #removeIndex}
      */
     @Override
-    public void deleteUnassignedIndex(String reason, IndexMetadata oldIndexMetadata, ClusterState clusterState) {
+    public void deleteUnassignedIndex(String reason, IndexMetadata oldIndexMetadata, @Nullable ProjectMetadata project) {
         if (nodeEnv.hasNodeFile()) {
             Index index = oldIndexMetadata.getIndex();
             try {
-                if (clusterState.metadata().getProject().hasIndex(index)) {
-                    final IndexMetadata currentMetadata = clusterState.metadata().getProject().index(index);
+                if (project != null && project.hasIndex(index)) {
+                    final IndexMetadata currentMetadata = project.index(index);
                     throw new IllegalStateException(
                         "Can't delete unassigned index store for ["
                             + index.getName()

server/src/main/java/org/elasticsearch/indices/cluster/IndicesClusterStateService.java

@@ -400,7 +400,11 @@ private void deleteIndices(final ClusterChangedEvent event) {
                 indexServiceClosedListener = SubscribableListener.nullSuccess();
                 final IndexMetadata metadata = project.get().index(index);
                 indexSettings = new IndexSettings(metadata, settings);
-                indicesService.deleteUnassignedIndex("deleted index was not assigned to local node", metadata, state);
+                indicesService.deleteUnassignedIndex(
+                    "deleted index was not assigned to local node",
+                    metadata,
+                    state.metadata().projects().get(project.get().id())
+                );
             } else {
                 // The previous cluster state's metadata also does not contain the index,
                 // which is what happens on node startup when an index was deleted while the
@@ -1258,7 +1262,7 @@ U createIndex(IndexMetadata indexMetadata, List<IndexEventListener> builtInIndex
          * Deletes an index that is not assigned to this node. This method cleans up all disk folders relating to the index
          * but does not deal with in-memory structures. For those call {@link #removeIndex}
          */
-        void deleteUnassignedIndex(String reason, IndexMetadata metadata, ClusterState clusterState);
+        void deleteUnassignedIndex(String reason, IndexMetadata metadata, @Nullable ProjectMetadata project);
 
         /**
          * Removes the given index from this service and releases all associated resources. Persistent parts of the index

test/framework/src/main/java/org/elasticsearch/indices/cluster/AbstractIndicesClusterStateServiceTestCase.java

@@ -12,6 +12,7 @@
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.metadata.IndexMetadata;
+import org.elasticsearch.cluster.metadata.ProjectMetadata;
 import org.elasticsearch.cluster.node.DiscoveryNode;
 import org.elasticsearch.cluster.routing.IndexShardRoutingTable;
 import org.elasticsearch.cluster.routing.RoutingNode;
@@ -213,7 +214,7 @@ public IndexMetadata verifyIndexIsDeleted(Index index, ClusterState state) {
         }
 
         @Override
-        public void deleteUnassignedIndex(String reason, IndexMetadata metadata, ClusterState clusterState) {
+        public void deleteUnassignedIndex(String reason, IndexMetadata metadata, ProjectMetadata project) {
 
         }