From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 05 Oct 2012 02:44:40 GMT
Subject: Re: Ignore on commit
Message-ID: <7vwqz5vdrb.fsf@alter.siamese.dyndns.org>
In-Reply-To: <CAMK1S_jfdW3BepELgPPoUf3qWwmU-o3o8OpMVimdfkERUJkymQ@mail.gmail.com>

Sitaram Chamarty <sitaramc@gmail.com> writes:

>> Git ignore doesn't ignore tracked files.
>
> would 'git update-index --assume-unchanged' work in this case?  Didn't
> see it mentioned in any of the replies so far (but I have never used
> it myself)

The assume-unchanged bit is *not* an instruction to tell Git to
ignore changes.  It is your *promise* that you will not change it,
and tells Git that it is free to use the contents from the working
tree and the contents in the index interchangeably, taking whichever
is more convenient for Git to handle.

So, no, it might appear to work in some cases, but you are playing
with an undefined behaviour.