/**
 * Verifies that a write that sets the on-disk multikey flag does not generate prepare conflicts
 * that would lead to a deadlock during secondary oplog application.
 *
 * This is a regression test for SERVER-41766.
 *
 * @tags: [uses_transactions, uses_prepare_transaction]
 */
(function() {
"use strict";
load("jstests/core/txns/libs/prepare_helpers.js");

const replTest = new ReplSetTest({name: 'multikey_write_avoids_prepare_conflict', nodes: 2});
replTest.startSet();
replTest.initiate();

const dbName = "test";
const collName = "coll";

const primary = replTest.getPrimary();
const secondary = replTest.getSecondary();
const primaryColl = primary.getDB(dbName)[collName];

jsTestLog("Creating a collection and an index on the primary, with spec {x:1}.");
assert.commandWorked(primaryColl.createIndex({x: 1}));
replTest.awaitReplication();

const session = primary.startSession();
const sessionDB = session.getDatabase(dbName);
const sessionColl = sessionDB.getCollection(collName);

jsTestLog("Preparing a transaction on primary that should set the multikey flag.");
session.startTransaction();
// This write should update the multikey flag in the catalog but we don't want it to generate
// prepare conflicts. In general, it is always safe to set an index as multikey earlier than is
// necessary.
assert.commandWorked(sessionColl.insert({x: [1, 2]}));
PrepareHelpers.prepareTransaction(session);

jsTestLog("Switching primaries by stepping up node " + secondary);
replTest.stepUp(secondary);
const newPrimary = replTest.getPrimary();
const newPrimaryColl = newPrimary.getDB(dbName)[collName];

jsTestLog("Doing an insert on the new primary that should also try to set the multikey flag.");
assert.commandWorked(newPrimaryColl.insert({x: [3, 4]}));
replTest.awaitReplication();

jsTestLog("Aborting the prepared transaction on session " + tojson(session.getSessionId()));
assert.commandWorked(newPrimary.adminCommand({
    abortTransaction: 1,
    lsid: session.getSessionId(),
    txnNumber: session.getTxnNumber_forTesting(),
    autocommit: false
}));

replTest.stopSet();
}());