How bad is “if (!this)” in a C++ member function?

Question

If I come across old code that does if (!this) return; in an app, how severe a risk is this? Is it a dangerous ticking time bomb that requires an immediate app-wide

Answer 1

If it's something that's bothering you today, it'll bother you a year from now. As you pointed out, changing it will almost certainly introduce some bugs -- but you can begin by retaining the return NULL functionality, add a bit of logging, let it run in the wild for a few weeks, and find how many times it even gets hit?