From: Philip Oakley <philipoakley@iee.org>
Date: Tue, 16 Apr 2013 07:25:24 GMT
Subject: Re: [RFC/PATCH 0/2] Test the Git version string
Message-ID: <99AE5E981E2547B6A71A4D77B17167B9@PhilipOakley>
In-Reply-To: <7vli8k4lnj.fsf@alter.siamese.dyndns.org>

From: "Junio C Hamano" <gitster@pobox.com>
Sent: Monday, April 15, 2013 2:39 AM
> "Philip Oakley" <philipoakley@iee.org> writes:
>
>>> If the "parsing" is done for white/blacklist purposes, is there a
>>> need to straight-jacket the verison string format like this series?
>>
>> The purpose is to document what we felt we could guarantee, and that
>> which was open to variation, so that those, like the Git-Gui, can
>> code
>> in a sensible check for the version. Two digits (X.Y) should pass the
>> existing Git Gui check.
>>
>> I'll drop the length limit, and keep to an X.Y check
>>
>> Is the end of t0000-basic.sh a sensible place for the check?
>
> Sorry, but I still do not understand what you are trying to achieve.
>
> What kind of benefit are you envisioning out of this?

The purpose of tests is to detect mistakes and spot regressions.

A change to the 'git version X.Y.z' string would be a regression, as I 
spotted earlier, as it conflicts with expectations of standard 
programmes such as git-gui.

>For a future
> version, people would not know what incompatibilities it would
> introduce, so
>
> case "$(git version)" in
> "git verison"[2-9].*)
>        echo unsupported version
>                exit 1
>                ;;
> esac
>
> is a nonsense check.
>
> For all released versions, people know how they looked like
> and we
> do not have anything further to specify.  Git 1.5.0 will forever
> identify itself as:
>
> $ git version
>        git version 1.5.0
>
> Worse yet, for an untagged version, you may get something like
>
> git version 1.8.2.1-515-g78d2372

However, if it passes the test [all the tests], one expects it will be 
reasonably (almost completely) compatibility with external expectations, 
such as those of git gui.

The questions I'm posing is from the other direction - use of tests for 
quality control.

>
> and it may or may not behave the same way as 1.8.2.1 depending on
> what trait you are interested in.

That will depend on the tests if [deliberately?] failed.

I'll tidy up the patches and commit meesage and see how it looks then.

Philip