cache lookup error for shell type creation with incompatible output function (DDL deparsing bug) - Mailing list pgsql-hackers

Hi all,

I just bumped into the following problem in HEAD (1c41e2a):
=# create type my_array_float (INPUT = array_in, OUTPUT = array_out,
ELEMENT = float4, INTERNALLENGTH = 32);
ERROR:  XX000: cache lookup failed for type 0
LOCATION:  format_type_internal, format_type.c:135

First note that in ~9.4 the error message is correct:
=# create type my_array_float (INPUT = array_in, OUTPUT = array_out,
ELEMENT = float4, INTERNALLENGTH = 32);
ERROR:  42883: function array_out(my_array_float) does not exist
LOCATION:  findTypeOutputFunction, typecmds.c:1709

Now, the problem is caused by findTypeOutputFunction() in DefineType()
because process passes InvalidOid as type OID when creating a type
shell, root cause being a2e35b5 because of this:
+               address = TypeShellMake(typeName, typeNamespace, GetUserId());

The fix consists in being sure that typoid uses the OID of the type
shell created, aka the OID stored in adress.ObjectID. Attached is a
patch with a regression test checking for shell creation with
incompatible input/output functions (failure caused by output function
here though) able to check this code path.
Regards,
--
Michael