Re: Bad behaviour when inserting unspecified variable length

> Uh, what did your CREATE TYPE command look like, exactly? This sounds
> like you specified a default value for the datatype.

Okay, here's two examples;

CREATE TYPE WKB (
internallength = VARIABLE,
input = WKB_in,
output = WKB_out,
storage= extended
);

CREATE TYPE GEOMETRY (
alignment = double,
internallength = VARIABLE,
input = geometry_in,
output = geometry_out,
storage = main
);

I've tried the WKB type with a "DEFAULT = NULL" clause and all the
different storage types. The same problem occurs everytime.

Here's the create function statements for the _in and _out functions;

create function WKB_in(opaque)
RETURNS WKB
AS '@MODULE_FILENAME@','WKB_in'
LANGUAGE 'c' with (isstrict);

create function WKB_out(opaque)
RETURNS opaque
AS '@MODULE_FILENAME@','WKB_out'
LANGUAGE 'c' with (isstrict);

create function geometry_in(opaque)
RETURNS GEOMETRY
AS '@MODULE_FILENAME@'
LANGUAGE 'c' with (isstrict);

create function geometry_out(opaque)
RETURNS opaque
AS '@MODULE_FILENAME@'
LANGUAGE 'c' with (isstrict);

> Maybe you need to show us your datatype's I/O functions, too.

I dont thing they're important. WKB_in and geometry_in are *never*
called, and WKB_out and geometry_out are called with bad values. Only
one line of my code is executed in the _out functions.

WellKnownBinary *WKB = (WellKnownBinary *)
PG_DETOAST_DATUM(PG_GETARG_DATUM(0));

or

GEOMETRY *geom1 = (GEOMETRY *)
PG_DETOAST_DATUM(PG_GETARG_DATUM(0));

(See below for a simpler example)

> Since
> this works perfectly fine for the standard variable-length datatypes,

Yes, on system (7.1.2 under solaris) the following works;
create table ttt (i integer, mytext text);
insert into ttt values (1);
select * from ttt;
i | mytext
---+----
1 |
(1 row)

Here's the simplest example I can come up with to show the problem;

create function WKB_in2(opaque)
RETURNS WKB
AS
'/data1/Refractions/Projects/PostGIS/work_dave/postgis/libpostgis.so.0.5','WKB_in2'
LANGUAGE 'c' with (isstrict);

create function WKB_out2(opaque)
RETURNS opaque
AS
'/data1/Refractions/Projects/PostGIS/work_dave/postgis/libpostgis.so.0.5','WKB_out2'
LANGUAGE 'c' with (isstrict);

CREATE TYPE WKB (
internallength = VARIABLE,
input = WKB_in2,
output = WKB_out2,
storage= extended
);

dave=# create table m (i integer, mywkb wkb);
dave=# insert into m values (1);
dave=# select * from m;
i | mywkb
---+-------
1 | me
(1 row)

You'll also get this output from the printf in WKB_out (ASCII 45 is the
"-" char);
WKB_out2: WKB has length 5 and 1st value 45

typedef struct Well_known_bin {
int32 size; // total size of this structure
unsigned char data[1]; //THIS HOLDS VARIABLE LENGTH DATA
} WellKnownBinary;

PG_FUNCTION_INFO_V1(WKB_in2);
Datum WKB_in2(PG_FUNCTION_ARGS)
{
char *str = PG_GETARG_CSTRING(0);

printf("I never get here!\n");

PG_RETURN_NULL();
}

PG_FUNCTION_INFO_V1(WKB_out2);
Datum WKB_out2(PG_FUNCTION_ARGS)
{
WellKnownBinary *WKB = (WellKnownBinary *)
PG_DETOAST_DATUM(PG_GETARG_DATUM(0));
char *result;

printf("WKB_out2: WKB has length %i and 1st value %i\n", WKB->size,
(int) ((char *)WKB)[4] );

// return something

result = palloc(3);
result[0] = 'm';
result[1] = 'e';
result[2] = 0;

PG_RETURN_CSTRING(result);
}