ESQL: mv_expand after sort fails

[astefan]

Description

FROM employees | sort emp_no | mv_expand job_positions

results in

                "type": "esql_illegal_argument_exception",
                "reason": "unknown physical plan node [OrderExec]",

[2023-09-27T18:52:46,078][INFO ][o.e.x.e.a.RestEsqlQueryAction] [runTask-0] Beginning execution of ESQL query.
Query string: [FROM employees | sort emp_no | mv_expand job_positions]
[2023-09-27T18:52:46,369][WARN ][r.suppressed             ] [runTask-0] path: /_query, params: {format=txt} org.elasticsearch.xpack.esql.EsqlIllegalArgumentException: unknown physical plan node [OrderExec]
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.plan(LocalExecutionPlanner.java:214)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.planMvExpand(LocalExecutionPlanner.java:561)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.plan(LocalExecutionPlanner.java:189)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.planLimit(LocalExecutionPlanner.java:556)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.plan(LocalExecutionPlanner.java:187)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.planOutput(LocalExecutionPlanner.java:275)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.plan(LocalExecutionPlanner.java:209)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.plan(LocalExecutionPlanner.java:155)
        at org.elasticsearch.xpack.esql.plugin.ComputeService.runCompute(ComputeService.java:256)
        at org.elasticsearch.xpack.esql.plugin.ComputeService.lambda$execute$4(ComputeService.java:167)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.action.ActionListenerImplementations$ResponseWrappingActionListener.onResponse(ActionListenerImplementations.java:236)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.action.ActionListenerImplementations$MappedActionListener.onResponse(ActionListenerImplementations.java:95)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.action.support.ContextPreservingActionListener.onResponse(ContextPreservingActionListener.java:32)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.action.ActionListenerResponseHandler.handleResponse(ActionListenerResponseHandler.java:49)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.transport.TransportService$UnregisterChildTransportResponseHandler.handleResponse(TransportService.java:1695)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.transport.TransportService$ContextRestoreResponseHandler.handleResponse(TransportService.java:1411)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.transport.TransportService$DirectResponseChannel.processResponse(TransportService.java:1510)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.transport.TransportService$DirectResponseChannel$1.doRun(TransportService.java:1487)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:26)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.common.util.concurrent.TimedRunnable.doRun(TimedRunnable.java:33)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingAbstractRunnable.doRun(ThreadContext.java:983)
        at org.elasticsearch.server@8.11.0-SNAPSHOT/org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:26)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
        at java.base/java.lang.Thread.run(Thread.java:1583)

[elasticsearchmachine]

Pinging @elastic/es-ql (Team:QL)

[elasticsearchmachine]

Pinging @elastic/elasticsearch-esql (:Query Languages/ES|QL)