[Bug analyzer/98830] -Wanalyzer-null-argument on static_cast and inheritance

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98830

--- Comment #1 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
Why is it a false positive?  The call to p->f () is a call to
  B* B::f ();
and that could return NULL, hence the call to C::g would be passing NULL as
'this'.

Arguably the message would be more readable as "possible false positive" and
the path ought to express that it happens when B::f returns NULL.