Re: [PATCH (1b)] merge-recursive.c: Add more generic merge_recursive_generic()

> merge_recursive_generic() takes, in comparison to to merge_recursive(),
> no commit ("struct commit *") arguments but SHA ids ("unsigned char *"),
> and no commit list of bases but an array of refs ("const char **").
> 
> This makes it more generic in the case that it can also take the SHA
> of a tree to merge trees without commits, for the bases, the head
> and the remote.
> 
> merge_recursive_generic() also handles locking and updating of the
> index, which is a common use case of merge_recursive().
> 
> This patch also rewrites builtin-merge-recursive.c to make use of
> merge_recursive_generic().  By doing this, I stumbled over the
> limitation of 20 bases and I've added a warning if this limitation
> is exceeded.
> 
> This patch qualifies make_virtual_commit() as static again because
> this function is not needed anymore outside merge-recursive.c.