pgsql: Prevent stack overflow in container-type functions.

Prevent stack overflow in container-type functions.

A range type can name another range type as its subtype, and a record
type can bear a column of another record type. Consequently, functions
like range_cmp() and record_recv() are recursive. Functions at risk
include operator family members and referents of pg_type regproc
columns. Treat as recursive any such function that looks up and calls
the same-purpose function for a record column type or the range subtype.
Back-patch to 9.0 (all supported versions).

An array type's element type is never itself an array type, so array
functions are unaffected. Recursion depth proportional to array
dimensionality, found in array_dim_to_jsonb(), is fine thanks to MAXDIM.

Branch
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REL9_0_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/0398e071adf5437bafaab7701dc46df55dceca76

Modified Files
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src/backend/utils/adt/rowtypes.c | 13 +++++++++++++
1 file changed, 13 insertions(+)