Actually it seems better to just get rid of the extra varargs function
and just have a single exec_prog. The extra NULL argument is not
troublesome enough, it seems. Updated version attached.
Again, win32 testing would be welcome. Sadly, buildfarm does not run
pg_upgrade's "make check".
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Álvaro Herrera http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services