masarati@aero.polimi.it writes:

...

struct berval x = BER_BVC("cn=foo");
dnParent(x, x);

keeps x.bv_val pointing at "cn=foo" instead of at the \0 behind it. bv_len is correctly set to 0 though.

Could be sort of intentional. As far as I remember, dnParent() is supposed to leave the second argument untouched, as it is often used on read-only data.

s/second/first/, but yes. With pdn=dn though (both args equal), the code first reset pdn->bv_val and then used that value. Swapping it makes more sense, and ensures that the output value is independent of whether or not pdn == dn.

Probably, the most appropriate fix consists in passing a temporary as the first argument.

No, the comment above the function says that pdn can be == dn.