fdw_scan_tlist for foreign table scans breaks EPQ testing, doesn't it?

Hi,

The latest foreign-join pushdown patch allows fdw_scan_tlist to be set
to a targetlist even for simple foreign table scans.  However, since I
think we assume that the test tuple of a foreign table for an EPQ
testing, whether it may be copied from the whole-row var or returned by
the RefetchForeignRow routine, has the rowtype declared for the foreign
table, ISTM that EPQ testing doesn't work properly in such a case since
that the targetlist and qual are adjusted to reference fdw_scan_tlist in
such a case.  Maybe I'm missing something though.

I don't understand custom scans/joins exactly, but I have a similar
concern for the simple-custom-scan case too.

Best regards,
Etsuro Fujita