chore: import upstream snapshot with attribution

testing/go/regression/tests/create_cast.sql

@@ -0,0 +1,54 @@
+--
+-- CREATE_CAST
+--
+
+-- Create some types to test with
+CREATE TYPE casttesttype;
+
+CREATE FUNCTION casttesttype_in(cstring)
+   RETURNS casttesttype
+   AS 'textin'
+   LANGUAGE internal STRICT IMMUTABLE;
+CREATE FUNCTION casttesttype_out(casttesttype)
+   RETURNS cstring
+   AS 'textout'
+   LANGUAGE internal STRICT IMMUTABLE;
+
+CREATE TYPE casttesttype (
+   internallength = variable,
+   input = casttesttype_in,
+   output = casttesttype_out,
+   alignment = int4
+);
+
+-- a dummy function to test with
+CREATE FUNCTION casttestfunc(casttesttype) RETURNS int4 LANGUAGE SQL AS
+$$ SELECT 1; $$;
+
+SELECT casttestfunc('foo'::text); -- fails, as there's no cast
+
+-- Try binary coercion cast
+CREATE CAST (text AS casttesttype) WITHOUT FUNCTION;
+SELECT casttestfunc('foo'::text); -- doesn't work, as the cast is explicit
+SELECT casttestfunc('foo'::text::casttesttype); -- should work
+DROP CAST (text AS casttesttype); -- cleanup
+
+-- Try IMPLICIT binary coercion cast
+CREATE CAST (text AS casttesttype) WITHOUT FUNCTION AS IMPLICIT;
+SELECT casttestfunc('foo'::text); -- Should work now
+
+-- Try I/O conversion cast.
+SELECT 1234::int4::casttesttype; -- No cast yet, should fail
+
+CREATE CAST (int4 AS casttesttype) WITH INOUT;
+SELECT 1234::int4::casttesttype; -- Should work now
+
+DROP CAST (int4 AS casttesttype);
+
+-- Try cast with a function
+
+CREATE FUNCTION int4_casttesttype(int4) RETURNS casttesttype LANGUAGE SQL AS
+$$ SELECT ('foo'::text || $1::text)::casttesttype; $$;
+
+CREATE CAST (int4 AS casttesttype) WITH FUNCTION int4_casttesttype(int4) AS IMPLICIT;
+SELECT 1234::int4::casttesttype; -- Should work now