Re: [PATCH] Remove useless if-before-free tests.

> I am not interested in automating useless "if (x) free(x)"
> tests, but one thing I recently wanted but did not know a handy
> tool for was to find all the calls to free() that free a pointer
> to an object of a particular type.  More specifically, we seem
> to allocate and free many "struct commit_list", and I wanted to
> introduce a custom bulk allocator.  Allocate many of them in a
> block, hand out one by one, and tell callers to hand them back
> not to free() but to the allocator so that it can keep the
> returned ones on a linked list and hand them back again when the
> next call wanted to allocate one without actually calling
> xmalloc()).  But in order to do so, missed conversion from
> malloc() to the custom allocator is not fatal (just wasteful),
> but forgetting to convert free() really is.