You're right that it's not needed in my example but sometimes the thing that you're freeing has pointers inside it which themselves have to be freed first and in that case you need the if.
There are several other issues I haven't shown like what happens if you need to free something only when the return code is "FALSE" indicating that something failed.
This is not as nice as defer but up till now it was a comparatively nice way to deal with those functions which were really large and complicated and had many exit points.
If you have something which contains pointers, you should have a destructor function for it, which itself should check if the pointer is not NULL before attempting to free any fields.
We are talking about C. A destructor function in C is a function that gets called when the library gets unloaded. No you shouldn't have a destructor function for it.
There are several other issues I haven't shown like what happens if you need to free something only when the return code is "FALSE" indicating that something failed.
This is not as nice as defer but up till now it was a comparatively nice way to deal with those functions which were really large and complicated and had many exit points.