Kyotaro> Hello, this looks to be a kind of thinko. The attached patch Kyotaro> fixes it.
No, that's still wrong. Just knowing that there is a List is not enough to tell whether to concat it or append it.
Jeevan's original patch tries to get around this by making the RowExpr case wrap another List around its result (which is then removed by the concat), but this is the wrong approach too because it breaks nested RowExprs (which isn't valid syntax in the spec, because the spec allows only column references in GROUP BY, not arbitrary expressions, but which we have no reason not to support).
Attached is the current version of my fix (with Jeevan's regression tests plus one of mine).
Looks good to me.
-- Andrew (irc:RhodiumToad)
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Jeevan B Chalke Principal Software Engineer, Product Development EnterpriseDB Corporation The Enterprise PostgreSQL Company