Re: [PATCH] git-rebase.txt: add another hook to the hooks section, and explain more

>  The apply backend has not traditionally called the post-commit hook,
> +while the merge backend has.  In contrast, the apply backend has
> +traditionally called the post-checkout hook while the merge backend
> +has not.  However, the calling of these hooks in both cases was by
> +accident of implementation rather than by design (both backends were
> +originally implemented as shell scripts and happened to invoke other
> +commands like 'git checkout' or 'git commit' that would call the
> +hooks).  Both backends should have the same behavior, though it is not
> +entirely clear which, if any, is correct.  We will likely remove both
> +of these hooks in the future.