advance_mut implementation of BufMut for Vec<u8> seems inconsistent with documentation

[udoprog]

The documentation of BufMut::advance_mut states the following about panics:

Panics

This function may panic if cnt > self.remaining_mut().

Implementer notes

It is recommended for implementations of advance_mut to panic if
cnt > self.remaining_mut(). If the implementation does not panic,
the call must behave as if cnt == self.remaining_mut().

A call with cnt == 0 should never panic and be a no-op.

Currently, the impl for Vec<u8> will reserve to accommodate the advance. This seems to be in conflict with If the implementation does not panic, the call must behave as if cnt == self.remaining_mut().