Accessing system.namespaces cursor with pending data after removing namespaces may cause crash

use system_namespaces_invalidations; let dbName = 'system_namespaces_invalidations' ; let num_collections = 3; for (let i = 0; i < num_collections; i++) { assert.commandWorked(db.createCollection( 'coll' + i.toString())); } let cmd = db.system.namespaces.count() ? {find: 'system.namespaces' } : {listCollections: dbName}; Object.extend(cmd, {batchSize: 2}); let res = db.runCommand(cmd); assert.commandWorked(res, 'could not run ' + tojson(cmd)); let cursor = new DBCommandCursor(db.getMongo(), res); let errMsg = 'expected more data from command ' + tojson(cmd) + ', with result ' + tojson(res); assert(cursor.hasNext(), errMsg); for (let j = 0; j < num_collections; j++) { assert(db[ 'coll' + j.toString()].drop()); } assert.gt(cursor.itcount(), 0, errMsg);