Re: [RFC/PATCH] Make --full-history consider more merges

[Junio C Hamano <gitster@pobox.com>]

Kevin Bracey <kevin@bracey.fi> writes:

> diff --git a/revision.c b/revision.c
> index eb98128..96fe3f5 100644
> --- a/revision.c
> +++ b/revision.c
> @@ -516,8 +516,14 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
>  		}
>  		die("bad tree compare for commit %s", sha1_to_hex(commit->object.sha1));
>  	}
> -	if (tree_changed && !tree_same)
> -		return;
> +
> +	if (tree_changed) {
> +		if (!tree_same)
> +			return;
> +
> +		if (!revs->simplify_history && !revs->simplify_merges)
> +			return;

So in addition to "have some change and there is no same parent"
case, under _some_ condition we avoid marking a merge not worth
showing (i.e. TREESAME) if there is any change.

And the condition is !simplify_history and !simplify_merges, which
would cover --full-history, but I am not sure if requiring
!simplify_merges is correct.

Do you need it and if so why?  The --simplify-merges option is
defined as a post-processing operation over what full-history
produces in the list limiting code (which involves the logic the
patch is touching).  The --ancestry-path option works the same way
but its post-processing is done inside the limit_list() function.

So it feels more natural if the patch were ignoring simplify_merges
and paid attention only to simplify_history.

> +	}
>  	commit->object.flags |= TREESAME;
>  }