From: Anders Höckersten <anders@hockersten.se>
Date: Sun, 16 May 2021 12:47:49 GMT
Subject: Re: [PATCH] describe-doc: clarify default length of abbreviation
Message-ID: <8cad4c4b-a923-43f2-9bb7-6ce418cfb0fc@www.fastmail.com>
In-Reply-To: <1dc7877e-adb4-e3f5-3b59-bd45f9673596@gmail.com>



On Sun, May 16, 2021, at 14:00, Bagas Sanjaya wrote:
> On 16/05/21 14.32, Anders Höckersten via GitGitGadget wrote:
>   >   --abbrev=<n>::
> > -	Instead of using the default 7 hexadecimal digits as the
> > -	abbreviated object name, use <n> digits, or as many digits
> > -	as needed to form a unique object name.  An <n> of 0
> > -	will suppress long format, only showing the closest tag.
> > +	Instead of using the default number of hexadecimal digits (which
> > +	will vary according to the size of the repository with a default of
> > +	7) of the abbreviated object name, use <n> digits, or as many digits
> > +	as needed to form a unique object name.  An <n> of 0 will suppress
> > +	long format, only showing the closest tag.
> >   
> 
> I think the more correct is the abbreviated hash length is determined
> by number of objects.

I agree. I will modify this to:  "(which will vary according to the number of objects in the repository with a default of 7)" unless you have a different suggestion.

> >   --candidates=<n>::
> >   	Instead of considering only the 10 most recent tags as
> > @@ -139,8 +140,11 @@ at the end.
> >   
> >   The number of additional commits is the number
> >   of commits which would be displayed by "git log v1.0.4..parent".
> > -The hash suffix is "-g" + unambiguous abbreviation for the tip commit
> > -of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`).
> > +The hash suffix is "-g" + an unambigous abbreviation for the tip commit
> > +of parent (which was `2414721b194453f058079d897d13c4e377f92dc6`). The
> > +length of the abbreviation scales as the repository grows, using the
> > +approximate number of objects in the repository and a bit of math
> > +around the birthday paradox, and defaults to a minimum of 7.
> 
> What is the birthday paradox then?
> 
> Also, better say "... and by default the minimum length is 7.".

The explanation was mostly copied from the 2.11.0 release notes, but mentioning the birtday paradox is unnecessary. I suggest changing this sentence to:
"The length of the abbreviation scales as the repository grows using the approximate number of objects in the repository, and by default the minimum length is 7."

Best regards,
Anders