pgsql: The result of a FULL or RIGHT join can't be assumed to be sorted

Log Message:
-----------
The result of a FULL or RIGHT join can't be assumed to be sorted by the
left input's sorting, because null rows may be inserted at various points.
Per report from Ferenc Lutisch��n.

Tags:
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REL7_2_STABLE

Modified Files:
--------------
    pgsql/src/backend/optimizer/path:
        joinpath.c (r1.67 -> r1.67.2.1)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/path/joinpath.c.diff?r1=1.67&r2=1.67.2.1)
        pathkeys.c (r1.36 -> r1.36.2.1)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/optimizer/path/pathkeys.c.diff?r1=1.36&r2=1.36.2.1)
    pgsql/src/include/optimizer:
        paths.h (r1.59 -> r1.59.2.1)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/optimizer/paths.h.diff?r1=1.59&r2=1.59.2.1)