Problem with heap_form_tuple error

Hi all,

I'm have a problem with heap_form_tuple error
    ERROR:  invalid memory alloc request size 1149502660

I've read through a ton of examples and read through the code and the
docs and I'm sure I'm doing something stupid but I'm not seeing it. I
have included a very reduced sample of the code below trying to focus on
the relevant parts.

1. how I get my return tuple_desc
2. how I prepare my values and nulls arrays

I am totally stuck on this! So I really need some help to point out the
error of my ways here.

Thanks,
   -Steve

     if (SRF_IS_FIRSTCALL()) {
         MemoryContext   oldcontext;

         /* create a function context for cross-call persistence */
         funcctx = SRF_FIRSTCALL_INIT();

         /* create a function context for cross-call persistence */
         oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);

         ...

         if (get_call_result_type( fcinfo, NULL, &tuple_desc ) !=
TYPEFUNC_COMPOSITE ) {
             elog(ERROR, "function returning record called in context"
                 " that cannot accept type record");
             std_free(std);
             return finish(-1);
         }
         /* since this is a defined composite type,
            I probably do not need to bless it,
            but the example in the docs said to */
         BlessTupleDesc(tuple_desc);
         /* save this for later usage also */
         funcctx->tuple_desc = tuple_desc;

         MemoryContextSwitchTo(oldcontext);

         DBG("finished first call setup");
     }

     funcctx = SRF_PERCALL_SETUP();

     call_cntr  = funcctx->call_cntr;
     max_calls  = funcctx->max_calls;
     tuple_desc = funcctx->tuple_desc;  /* the result record description */
     fctx       = (std_fctx *) funcctx->user_fctx;
     std        = fctx->std;

     ...

     if (call_cntr < max_calls) { /* do while there are more to send */
         Datum *values;
         bool *nulls;
         int id;
         int k;

         HeapTuple addr_tuple = spi_tuptable->vals[call_cntr];

         ...

         values = (Datum *) palloc(17 * sizeof(Datum));
         nulls = (bool *) palloc(17 * sizeof(bool));
         for (k=0; k<17; k++) {
             values[k] = (Datum) 0;
             nulls[k] = true;
         }
         values[0] = Int32GetDatum(id);
         nulls[0] = false;
         if (stdaddr->building) {
             DBG("building %d", strlen(stdaddr->building));
             values[1] = CStringGetDatum(pstrdup(stdaddr->building));
             nulls[1] = false;
         }
         ... more if blocks for values[2..15] ...
         if (stdaddr->unit) {
             DBG("unit %d", strlen(stdaddr->unit));
             values[16] = CStringGetDatum(pstrdup(stdaddr->unit));
             nulls[16] = false;
         }
         HeapTuple tuple = heap_form_tuple(tuple_desc, values, nulls);
         result = HeapTupleGetDatum(tuple);
         SRF_RETURN_NEXT(funcctx, result);
     }
     ...

when this runs DBG logs the following:

NOTICE:  city='NORTH CHELMSFORD', state='MASSACHUSETTS', postcode='01863'
NOTICE:  setup values and nulls array for natts=17
NOTICE:  house_num 2
NOTICE:  name 8
NOTICE:  suftype 4
NOTICE:  city 16
NOTICE:  state 13
NOTICE:  postcode 5
NOTICE:  calling heap_form_tuple
ERROR:  invalid memory alloc request size 1149502660

the stdaddr fields all have reasonable null terminated CStrings in them.