Race condition during initial sync when index builds start in data cloning phase

/** * */   (function() { 'use strict'; load("jstests/libs/fail_point_util.js"); load('jstests/replsets/rslib.js'); const basename = 'initial_sync_rename_database_before_cloning'; jsTestLog('Bring up a replica set'); const rst = new ReplSetTest({name: basename, nodes: 1}); rst.startSet(); rst.initiate(); const dbName = "test"; const primary = rst.getPrimary(); const primaryDb = primary.getDB(dbName); jsTestLog("Create collections on primary"); const collName = "coll"; jsTestLog('Waiting for replication'); rst.awaitReplication(); jsTestLog('Bring up a new node'); const secondary = rst.add({setParameter: 'numInitialSyncAttempts=1'}); // Add a fail point that causes the secondary's initial sync to hang before // copying databases. const failPoint = configureFailPoint(secondary, 'initialSyncHangBeforeCopyingDatabases'); jsTestLog('Begin initial sync on secondary'); let conf = rst.getPrimary().getDB('admin').runCommand({replSetGetConfig: 1}).config; conf.members.push({_id: 1, host: secondary.host, priority: 0, votes: 0}); conf.version++; assert.commandWorked(rst.getPrimary().getDB('admin').runCommand({replSetReconfig: conf})); assert.eq(primary, rst.getPrimary(), 'Primary changed after reconfig'); // Confirm that initial sync started on the secondary node. jsTestLog('Waiting for initial sync to start'); failPoint.wait();   assert.commandWorked(primaryDb.getCollection(collName).insert({})); assert.commandWorked(primaryDb.runCommand({emptycapped: "coll"})) assert.commandWorked(primaryDb.getCollection(collName).insert({_id: 0, a: 1})); jsTestLog('Build index on the sync source'); const fpIndexSrc = configureFailPoint(primary, 'hangAfterStartingIndexBuild'); const awaitIndex = startParallelShell(() => { assert.commandWorked(db.getCollection('coll').createIndex({a: 1})); }, primary.port) jsTestLog('Pause index build on sync source') fpIndexSrc.wait(); const fpIndexInit = configureFailPoint(secondary, 'hangAfterStartingIndexBuild'); jsTestLog('Resume the initial sync') failPoint.off();   jsTestLog('Pause index build on initial sync node'); fpIndexInit.wait(); jsTestLog('Resume index build on sync source to finish'); fpIndexSrc.off();   awaitIndex();   jsTestLog('Resume index build on initial sync node to finish'); fpIndexInit.off(); jsTestLog('Wait for both nodes to be up-to-date');   rst.awaitSecondaryNodes(); rst.awaitReplication();   rst.checkReplicatedDataHashes(); rst.checkOplogs(); rst.stopSet(); })();