Re: [PATCH] rev-list-options: clarify the usage of -n/--max-number

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

Pranit Bauva <pranit.bauva@gmail.com> writes:

> -n=<number>, -<number>, --max-number=<number> shows the last n commits
> specified in <number> irrespective of whether --reverse is used or not.
> With --reverse, it just shows the last n commits in reverse order.

I think it is easier to understand if you updated the description of
"--reverse", rather than "-<n>".  "rev-list -n $N" that stops after
showing $N commits is something everybody understands.  What often
dissapoints some users is that "--reverse" kicks in _after_ what
commits are to be shown are decided.

>  Documentation/rev-list-options.txt | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
> index 7e462d3..6b7c2e5 100644
> --- a/Documentation/rev-list-options.txt
> +++ b/Documentation/rev-list-options.txt
> @@ -18,7 +18,7 @@ ordering and formatting options, such as `--reverse`.
>  -<number>::
>  -n <number>::
>  --max-count=<number>::
> -	Limit the number of commits to output.
> +	Limit to last n number of commits to output specified in <number>.

These essentially say the same thing.  The original does not mention
where and how <number> is used, but "Limit the number of commits" as
a description for "-<number>" would be understood by anybody halfway
intelligent that the given number is used as that limit, so I do not
think an updated description is making it easier to understand.

There is a paragraph of interest in an earlier part of "Commit
Limiting" section (which is the section "-n" appears in, among other
options):

    Note that these are applied before commit
    ordering and formatting options, such as `--reverse`.

So the documentation already makes an attempt to avoid confusion
Ruediger saw, i.e. "rev-list traverses, limits the output to N, and
then shows these N commits in reverse" is what it expects readers to
understand, and that it also expects it would lead naturally to
"these N commits are still from the newest part of the history,
hence 'rev-list --reverse -n N' is not how you grab the earliest N".

But apparently the attempt by the current documentation is not
enough.  Let's see how it describes the '--reverse' option:

    Commit Ordering
    ~~~~~~~~~~~~~~~

    By default, the commits are shown in reverse chronological order.
    ...

    --reverse::
            Output the commits in reverse order.
            Cannot be combined with `--walk-reflogs`.

Perhaps "Output the commits chosen to be shown (see Commit Limiting
section above) in reverse order." would make it clearer?