C trigger problem : conversion of CString to Datum

Hello,

I cannot convert properly a cstring to a Datum :
Here my code :
int attColNumber;
Datum new_barcode;
bool isnull = 0;
char barcode[14];

elog(INFO, "gd_trigfunc_before_article_insert() : bar_code = %s",
barcode);
attColNumber = COL_BARCODE;
new_barcode = CStringGetDatum(barcode);
workTuple = SPI_modifytuple(trigdata->tg_relation,
trigdata->tg_trigtuple, 1, &attColNumber, &new_barcode, &isnull);

the result :

# INSERT INTO t_articles VALUES (4001, 1, '065', 'White', NULL, 'XS', null);
INFO: gd_trigfunc_before_article_insert() : bar_code = 5492850000012
INSERT 0 1
# select * from t_articles WHERE k_id > 2000;
k_id | product_id | color_id | color_desc | height | size | bar_code
------+------------+----------+------------+--------+------+--------------
4001 | 1 | 065 | White | | XS | 492850000012
(1 ligne)

Missing the firs digit of the barcode.

Thanks in advance for your help
Regards
Guy