Thread: pgsql: Fix numeric_maximum_size() calculation.

Log Message:
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Fix numeric_maximum_size() calculation.

The old computation can sometimes underestimate the necessary space
by 2 bytes; however we're not back-patching this, because this result
isn't used for anything critical.  Per discussion with Tom Lane,
make the typmod test in this function match the ones in numeric()
and apply_typmod() exactly.

Modified Files:
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    pgsql/src/backend/utils/adt:
        numeric.c (r1.125 -> r1.126)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/numeric.c?r1=1.125&r2=1.126)