refresh materialized view: concurrently + with no data

Hi, Hackers,
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When executing the command below:
    refresh materialized view concurrently MY_MATVIEW_2 with no data;
PostgreSQL throws the following error:
    ERROR:  REFRESH options CONCURRENTLY and WITH NO DATA cannot be used together.
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I noticed that this error is reported in the executor within RefreshMatViewByOid(), 
rather than being checked earlier during parsing in gram.y when building RefreshMatViewStmt. 
We can simply detect the conflict between n->concurrent and n->skipData at parse time.
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I’m curious whether this is a deliberate convention for PostgreSQL utility commands: 
  allowing conflicting option combinations to pass the parser, and deferring validity checks until executor execution?
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Any clarification is appreciated.
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Thanks,
--
ZizhuanLiu (X-MAN) 
44973863@qq.com