Adjust FailedShardsRoutingTests on main (#90218)

Ports some of the changes from #90211 to `main` to reduce the diff with
the branch.

server/src/test/java/org/elasticsearch/cluster/routing/allocation/FailedShardsRoutingTests.java

@@ -440,7 +440,7 @@ public class FailedShardsRoutingTests extends ESAllocationTestCase {
 
         logger.info("Adding two nodes and performing rerouting");
         clusterState = ClusterState.builder(clusterState)
-            .nodes(DiscoveryNodes.builder().add(newNode("node1")).add(newNode("node2")))
+            .nodes(DiscoveryNodes.builder().add(newNode("node1")).add(newNode("node2")).localNodeId("node1").masterNodeId("node1"))
             .build();
         clusterState = strategy.reroute(clusterState, "reroute");
 
@@ -535,7 +535,15 @@ public class FailedShardsRoutingTests extends ESAllocationTestCase {
 
         // add 4 nodes
         clusterState = ClusterState.builder(clusterState)
-            .nodes(DiscoveryNodes.builder().add(newNode("node1")).add(newNode("node2")).add(newNode("node3")).add(newNode("node4")))
+            .nodes(
+                DiscoveryNodes.builder()
+                    .add(newNode("node1"))
+                    .add(newNode("node2"))
+                    .add(newNode("node3"))
+                    .add(newNode("node4"))
+                    .localNodeId("node1")
+                    .masterNodeId("node1")
+            )
             .build();
         clusterState = ClusterState.builder(clusterState).routingTable(allocation.reroute(clusterState, "reroute").routingTable()).build();
         assertThat(shardsWithState(clusterState.getRoutingNodes(), INITIALIZING).size(), equalTo(1));
@@ -560,13 +568,19 @@ public class FailedShardsRoutingTests extends ESAllocationTestCase {
         ClusterState newState = applyFailedShard(allocation, clusterState, primaryShardToFail);
         assertThat(newState, not(equalTo(clusterState)));
         clusterState = newState;
-        // the primary gets allocated on another node, replicas are initializing
+
+        // The started replica gets promoted to primary and the initializing replica is reset. The other replica will be assigned.
         assertThat(shardsWithState(clusterState.getRoutingNodes(), STARTED).size(), equalTo(1));
         assertThat(shardsWithState(clusterState.getRoutingNodes(), INITIALIZING).size(), equalTo(2));
 
         ShardRouting newPrimaryShard = clusterState.routingTable().index("test").shard(0).primaryShard();
         assertThat(newPrimaryShard, not(equalTo(primaryShardToFail)));
         assertThat(newPrimaryShard.allocationId(), equalTo(startedReplica.allocationId()));
+
+        // Another reroute changes nothing
+        clusterState = allocation.reroute(clusterState, "test");
+        assertThat(shardsWithState(clusterState.getRoutingNodes(), STARTED).size(), equalTo(1));
+        assertThat(shardsWithState(clusterState.getRoutingNodes(), INITIALIZING).size(), equalTo(2));
     }
 
     public void testFailAllReplicasInitializingOnPrimaryFailWhileHavingAReplicaToElect() {
@@ -609,11 +623,18 @@ public class FailedShardsRoutingTests extends ESAllocationTestCase {
         ClusterState newState = applyFailedShard(allocation, clusterState, primaryShardToFail);
         assertThat(newState, not(equalTo(clusterState)));
         clusterState = newState;
+
+        // The started replica gets promoted to primary and the initializing replica is reset. The other replica will be assigned.
         assertThat(shardsWithState(clusterState.getRoutingNodes(), STARTED).size(), equalTo(1));
         assertThat(shardsWithState(clusterState.getRoutingNodes(), INITIALIZING).size(), equalTo(2));
 
         ShardRouting newPrimaryShard = clusterState.routingTable().index("test").shard(0).primaryShard();
         assertThat(newPrimaryShard, not(equalTo(primaryShardToFail)));
+
+        // Another reroute changes nothing
+        clusterState = allocation.reroute(clusterState, "test");
+        assertThat(shardsWithState(clusterState.getRoutingNodes(), STARTED).size(), equalTo(1));
+        assertThat(shardsWithState(clusterState.getRoutingNodes(), INITIALIZING).size(), equalTo(2));
     }
 
     public void testReplicaOnNewestVersionIsPromoted() {