Function GUCArrayDelete

src/backend/utils/misc/guc.c:11746–11810

* Delete an entry from an option array. The array parameter may be NULL * to indicate the current table entry is NULL. Also, if the return value * is NULL then a null should be stored. */

 * is NULL then a null should be stored.
 */
ArrayType *
GUCArrayDelete(ArrayType *array, const char *name)
{
	struct config_generic *record;
	ArrayType  *newarray;
	int			i;
	int			index;

	Assert(name);

	/* test if the option is valid and we're allowed to set it */
	(void) validate_option_array_item(name, NULL, false);

	/* normalize name (converts obsolete GUC names to modern spellings) */
	record = find_option(name, false, true, WARNING);
	if (record)
		name = record->name;

	/* if array is currently null, then surely nothing to delete */
	if (!array)
		return NULL;

	newarray = NULL;
	index = 1;

	for (i = 1; i <= ARR_DIMS(array)[0]; i++)
	{
		Datum		d;
		char	   *val;
		bool		isnull;

		d = array_ref(array, 1, &i,
					  -1 /* varlenarray */ ,
					  -1 /* TEXT's typlen */ ,
					  false /* TEXT's typbyval */ ,
					  TYPALIGN_INT /* TEXT's typalign */ ,
					  &isnull);
		if (isnull)
			continue;
		val = TextDatumGetCString(d);

		/* ignore entry if it's what we want to delete */
		if (strncmp(val, name, strlen(name)) == 0
			&& val[strlen(name)] == '=')
			continue;

		/* else add it to the output array */
		if (newarray)
			newarray = array_set(newarray, 1, &index,
								 d,
								 false,
								 -1 /* varlenarray */ ,
								 -1 /* TEXT's typlen */ ,
								 false /* TEXT's typbyval */ ,
								 TYPALIGN_INT /* TEXT's typalign */ );
		else
			newarray = construct_array(&d, 1,
									   TEXTOID,