SOLR-10196: ElectionContext#runLeaderProcess can hit NPE on core close.

solr/CHANGES.txt

@@ -186,6 +186,8 @@ Bug Fixes
 * SOLR-10055: Linux installer now renames existing bin/solr.in.* as bin/solr.in.*.orig to make the installed config in
   /etc/defaults be the one found by default when launching solr manually. (janhoy)
 
+* SOLR-10196: ElectionContext#runLeaderProcess can hit NPE on core close. (Mark Miller)
+
 Optimizations
 ----------------------
 

solr/core/src/java/org/apache/solr/cloud/ElectionContext.java

@@ -423,8 +423,12 @@ final class ShardLeaderElectionContext extends ShardLeaderElectionContextBase {
           
           super.runLeaderProcess(weAreReplacement, 0);
           try (SolrCore core = cc.getCore(coreName)) {
-            core.getCoreDescriptor().getCloudDescriptor().setLeader(true);
-            publishActiveIfRegisteredAndNotActive(core);
+            if (core != null) {
+              core.getCoreDescriptor().getCloudDescriptor().setLeader(true);
+              publishActiveIfRegisteredAndNotActive(core);
+            } else {
+              return;
+            }
           }
           log.info("I am the new leader: " + ZkCoreNodeProps.getCoreUrl(leaderProps) + " " + shardId);
           

solr/core/src/test/org/apache/solr/cloud/CleanupOldIndexTest.java

@@ -47,7 +47,7 @@ public class CleanupOldIndexTest extends SolrCloudTestCase {
   }
   
   @AfterClass
-  public static void teardownTestCases() throws Exception {
+  public static void afterClass() throws Exception {
 
     if (suiteFailureMarker.wasSuccessful()) {
       zkClient().printLayoutToStdOut();