Re: [PATCH] Do not send "want" lines for complete objects

> Junio C Hamano <junkio@cox.net> writes:
> 
> > Let's draw a single strand of pearl case to illustrate.  You
> > have a commit chain A->B->C->D, and the other end says she has
> > C.  At this point, telling her that you have C is enough, and by
> > not telling her about A and B, you would save her from depreting
> > MAX_HAVE slots.  Of course, if the other end has D as another
> > head, then the above logic would give "^D^" to rev-list as well,
> > telling it not to tell her about C, but that is what we want --
> > because she already knows you have C too when you tell her that
> > you have D.  I think I like this optimization.
> 
> This was subtly wrong.  ^D^ would barf if D is a tag that points
> at a non commit (refs/tags/v2.6.11-tree).  Also it would do a
> suboptimal thing for a merge commit, since it will not cull the
> second and later parents.

> +		    ((commit = (struct commit *) deref_tag(o)) != NULL) &&
> +		    (commit->object.type = commit_type)) {
> +			struct commit_list *p = commit->parents;
> +			while (p && rev_command_len + 44 < sizeof(rev_command)) {
>  				snprintf(rev_command + rev_command_len, 44,
> -					" ^%s^", sha1_to_hex(remote));
> +					 " ^%s",
> +					 sha1_to_hex(p->item->object.sha1));
>  				rev_command_len += 43;
> +				p = p->next;
>  			}

> -
> -			continue;
> +			if (!p)
> +				continue;
>  		}
>  
>  		packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
>