Function pull

bitcoin/block.c:10–28

Sets *cursor to NULL and returns NULL when a pull fails. */

/* Sets *cursor to NULL and returns NULL when a pull fails. */
static const u8 *pull(const u8 **cursor, size_t *max, void *copy, size_t n)
{
	const u8 *p = *cursor;

	if (*max < n) {
		*cursor = NULL;
		*max = 0;
		/* Just make sure we don't leak uninitialized mem! */
		if (copy)
			memset(copy, 0, n);
		return NULL;
	}
	*cursor += n;
	*max -= n;
	assert(p);
	if (copy)
		memcpy(copy, p, n);
	return memcheck(p, n);
}

static u32 pull_le32(const u8 **cursor, size_t *max)
{