Re: Possible bug: identical lines added/removed in git diff

From: Stefan Beller <sbeller@google.com>
Date: Aug 27, 2018, 17:47 UTC
Message-ID: <CAGZ79kZ1BVTLnNYSs+NjEO1T1-PySSdZzVU-0ZfivjT_pfvviQ@mail.gmail.com>
In-Reply-To: <CAE6=WB_4_PhjfQpubFcYkNKejfDr22s-y0nPQKw5Yd4GVaN4Yw@mail.gmail.com>

On Sun, Aug 26, 2018 at 6:54 PM Gabriel Holodak <gthepiper@gmail.com> wrote:

>
> I think I'm running into a bug with git diff on v2.18.0.

I cannot reproduce with the two files attached.

I suspected you might have a different diff algorithm configured,
so I tested
    git diff --no-index old new
    git diff --patience --no-index old new
    git diff --histogram --no-index old new

all of which do not reproduce the issue.

Are there any encoding issues locally (Which platform are you on?) or in transit (Could you re-download the files from [1] and confirm it still produces this bug?)

[1] https://public-inbox.org/git/CAE6=WB_4_PhjfQpubFcYkNKejfDr22s-y0nPQKw5Yd4GVaN4Yw@mail.gmail.com/

> where the "DWIDTH 8 0" and "BITMAP" lines are removed and added,
> despite being identical. It only seems to be happening around this
> section of the file, for the U+00F0 character. This also seems close
> to a minimal reproduction of the issue.

Could you cut down to a real minimal reproduction, i.e. just these 20 lines or so?

>  If I git add --patch and stage
> a few hunks, then the duplicated lines seem to disappear.

Do you have any smudge filters or configuration regarding line endings?

Are the lines really different or the same ? (Can you inspect with a hex editor, maybe there are different kinds of invisible white spaces?)

> Steps to reproduce:
> git diff --no-index unitera_bold_italic.bdf.old unitera_bold_italic.bdf.new
> (It also happens inside a repo, this just seemed the easiest way to
> demonstrate.)

Thanks, Stefan