[ovs-dev] [PATCH] LLDP: add new command to show LLDP neighbor info

[Ben Pfaff]

> >>> +        if (id != NULL) {
> >>
> >>It's safe to call free(NULL), so , please, don't check.
> > [Rick] Does it mean that we override the original free() method, so that it won't crash when we call free(NULL)? If so, that is good and I don't need to check here.
> 
> It's part of a C standard starting at least from C89:
> """
> 4.10.3.2 The free function
> ...
> If ptr is a null pointer, no action occurs.
> """
> 
> 'man 3 free' suggests the same.

It's also part of the coding style document (more for Rick than for
Ilya):

    Functions that destroy an instance of a dynamically-allocated type should
    accept and ignore a null pointer argument. Code that calls such a function
    (including the C standard library function ``free()``) should omit a
    null-pointer check. We find that this usually makes code easier to read.