Re: [Outreachy] Return value before or after free()?

> Unfortunately, compilers have gotten much more aggressive about assuming
> that undefined behavior never occurs and rewriting code based on that.
> clang is not as bad about doing that, but GCC is very aggressive about
> it.  There are multiple instances where NULL pointer checks have been
> optimized out because the compiler exploited undefined behavior to
> assume a pointer was never NULL.
> 
> In this case, the only case in which we can safely assume that this
> behavior is acceptable is that r is NULL, in which case C11 tells us
> that "no action occurs" due to the free. So the compiler could just
> optimize this out to a "return 0".  Just because it doesn't now doesn't
> mean we can assume it won't in the future, so we do need to fix this.
> 
> I'll send a patch.