From: Johannes Schindelin <Johannes.Schindelin@gmx.de>
To: Junio C Hamano <gitster@pobox.com>
Cc: "René Scharfe" <l.s.r@web.de>,
"Tilman Vogel" <tilman.vogel@web.de>,
git@vger.kernel.org
Subject: Re: [PATCH] patch-id: ignore newline at end of file in diff_flush_patch_id()
Date: Mon, 24 Aug 2020 14:42:05 +0200 (CEST) [thread overview]
Message-ID: <nycvar.QRO.7.76.6.2008241441410.56@tvgsbejvaqbjf.bet> (raw)
In-Reply-To: <xmqqblj7worr.fsf@gitster.c.googlers.com>
[-- Attachment #1: Type: text/plain, Size: 2897 bytes --]
Hi,
On Tue, 18 Aug 2020, Junio C Hamano wrote:
> René Scharfe <l.s.r@web.de> writes:
>
> > Whitespace is ignored when calculating patch IDs. This is done by
> > removing all whitespace from diff lines before hashing them, including
> > a newline at the end of a file. If that newline is missing, however,
> > diff reports that fact in a separate line containing "\ No newline at
> > end of file\n", and this marker is hashed like a context line.
>
> Ah, ouch.
>
> > This goes against our goal of making patch IDs independent of
> > whitespace. Use the same heuristic that 2485eab55cc (git-patch-id: do
> > not trip over "no newline" markers, 2011-02-17) added to git patch-id
> > instead and skip diff lines that start with a backslash and a space
> > and are longer than twelve characters.
>
> Good find of previous example. Excellent.
Yup. Looks good to me, too. Thank you!
Dscho
>
> > Reported-by: Tilman Vogel <tilman.vogel@web.de>
> > Initial-test-by: Tilman Vogel <tilman.vogel@web.de>
> > Signed-off-by: René Scharfe <l.s.r@web.de>
> > ---
> > diff.c | 2 ++
> > t/t3500-cherry.sh | 23 +++++++++++++++++++++++
> > 2 files changed, 25 insertions(+)
>
> Thanks.
>
> > diff --git a/diff.c b/diff.c
> > index f9709de7b45..f175019eb7a 100644
> > --- a/diff.c
> > +++ b/diff.c
> > @@ -6044,6 +6044,8 @@ static void patch_id_consume(void *priv, char *line, unsigned long len)
> > struct patch_id_t *data = priv;
> > int new_len;
> >
> > + if (len > 12 && starts_with(line, "\\ "))
> > + return;
> > new_len = remove_space(line, len);
> >
> > the_hash_algo->update_fn(data->ctx, line, new_len);
> > diff --git a/t/t3500-cherry.sh b/t/t3500-cherry.sh
> > index f038f34b7c0..2b8d9cb38ed 100755
> > --- a/t/t3500-cherry.sh
> > +++ b/t/t3500-cherry.sh
> > @@ -55,4 +55,27 @@ test_expect_success \
> > expr "$(echo $(git cherry master my-topic-branch) )" : "+ [^ ]* - .*"
> > '
> >
> > +test_expect_success 'cherry ignores whitespace' '
> > + git switch --orphan=upstream-with-space &&
> > + test_commit initial file &&
> > + >expect &&
> > + git switch --create=feature-without-space &&
> > +
> > + # A spaceless file on the feature branch. Expect a match upstream.
> > + printf space >file &&
> > + git add file &&
> > + git commit -m"file without space" &&
> > + git log --format="- %H" -1 >>expect &&
> > +
> > + # A further change. Should not match upstream.
> > + test_commit change file &&
> > + git log --format="+ %H" -1 >>expect &&
> > +
> > + git switch upstream-with-space &&
> > + # Same as the spaceless file, just with spaces and on upstream.
> > + test_commit "file with space" file "s p a c e" file-with-space &&
> > + git cherry upstream-with-space feature-without-space >actual &&
> > + test_cmp expect actual
> > +'
> > +
> > test_done
> > --
> > 2.28.0
>
next prev parent reply other threads:[~2020-08-24 12:43 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-23 14:42 [BUG] git-cherry false-positive on upstream new-line change at end-of-file Tilman Vogel
2020-08-10 11:01 ` Tilman Vogel
2020-08-18 22:08 ` [PATCH] patch-id: ignore newline at end of file in diff_flush_patch_id() René Scharfe
2020-08-18 22:52 ` Junio C Hamano
2020-08-24 12:42 ` Johannes Schindelin [this message]
2020-08-27 9:05 ` Tilman Vogel
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