threads / discuss / 59050

Ignored commits appearing in git blame

Subject: Ignored commits appearing in git blame

## tl;dr

4 messages between Jan 8, 2023 and Jan 10, 2023.

replies: 3people: 3as markdown or json

Julien ÉLIE· Jan 8, 2023, 09:27 UTC · lore

Hi all,

I'm facing an issue with the use of "git blame" which shows commits marked to be ignored.

We have a .git-blame-ignore-revs file that can be retrievable at <https://github.com/InterNetNews/inn/blob/main/.git-blame-ignore-revs>.

The Git command line I'm using is:
     git blame --ignore-revs-file .git-blame-ignore-revs radius.c

Here is an extract where commit 36944f2b16 appears at line 59, though it should be ignored (present in .git-blame-ignore-revs):

8e3e288fec (Marc G. Fournier 1998-12-29 13:19:05 +0000 50) int radport; 8e3e288fec (Marc G. Fournier 1998-12-29 13:19:05 +0000 51) char *lochost; a9d899ddbe (Russ Allbery 1999-11-29 01:40:47 +0000 52) int locport; 8e3e288fec (Marc G. Fournier 1998-12-29 13:19:05 +0000 53) 8e3e288fec (Marc G. Fournier 1998-12-29 13:19:05 +0000 54) char *prefix, *suffix; /* futz with the username, if necessary */ 9f21a39f37 (Katsuhiro Kondou 1999-06-12 09:33:48 +0000 55) int ignore_source; d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000 56) d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000 57) struct _rad_config_t *next; /* point to any additional servers */ 8e3e288fec (Marc G. Fournier 1998-12-29 13:19:05 +0000 58) } rad_config_t; 36944f2b16 (Julien ÉLIE 2021-10-31 10:04:59 +0100 59) d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000 60) typedef struct _sending_t { d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000 61) auth_req req; d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000 62) int reqlen;

When running git blame without ignoring revisions, commit 36944f2b16 appears at lines 54, 57 and 59:

8e3e288fec (Marc G. Fournier 1998-12-29 13:19:05 +0000 50) int radport; 8e3e288fec (Marc G. Fournier 1998-12-29 13:19:05 +0000 51) char *lochost; a9d899ddbe (Russ Allbery 1999-11-29 01:40:47 +0000 52) int locport; 8e3e288fec (Marc G. Fournier 1998-12-29 13:19:05 +0000 53) 36944f2b16 (Julien ÉLIE 2021-10-31 10:04:59 +0100 54) char *prefix, *suffix; /* futz with the username, if necessary */ 9f21a39f37 (Katsuhiro Kondou 1999-06-12 09:33:48 +0000 55) int ignore_source; d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000 56) 36944f2b16 (Julien ÉLIE 2021-10-31 10:04:59 +0100 57) struct _rad_config_t *next; /* point to any additional servers */ 8e3e288fec (Marc G. Fournier 1998-12-29 13:19:05 +0000 58) } rad_config_t; 36944f2b16 (Julien ÉLIE 2021-10-31 10:04:59 +0100 59) d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000 60) typedef struct _sending_t { d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000 61) auth_req req; d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000 62) int reqlen;

Shouldn't 36944f2b16 have disappeared from the output at line 59?

It should have been d65e228465 which already had that line, as it can be seen in the commit (line 53 at that time):
   https://github.com/InterNetNews/inn/blob/d65e228465700ff044b75aecacb7062d2a1250f9/authprogs/radius.c

The result of that command is the same as the one GitHub shows; you can therefore find the whole ouput here:

     https://github.com/InterNetNews/inn/blame/main/authprogs/radius.c

Commit 36944f2b16 is mentioned at lines 59, 129, 144, 293, etc. though present in .git-blame-ignore-revs. Yet, that very commit is correctly ignored at other places of the same file.

Other files and other commits in the project are also affected.  I can give more examples if needed.

Is it the expected behaviour of "git blame"? Is there a reason for these commits to appear in some portions of the blame output?

Thanks beforehand,

-- 
Julien ÉLIE

« – Cet homme qui est sorti du palais, nous renseignera peut-être sur la
     façon d'y entrer. Suivons-le.
   – Mais… Il sait sortir d'accord, mais rien ne prouve qu'il sache
     entrer, et… » (Astérix)

Junio C Hamano· Jan 9, 2023, 04:35 UTC · re: Julien ÉLIE · lore

Re: Ignored commits appearing in git blame

Julien ÉLIE <julien@trigofacile.com> writes:

[jc: redirecting to those who touched "blame-ignore" topic in the past]

Show 64 quoted lines

> Hi all,
>
> I'm facing an issue with the use of "git blame" which shows commits marked to be ignored.
>
> We have a .git-blame-ignore-revs file that can be retrievable at <https://github.com/InterNetNews/inn/blob/main/.git-blame-ignore-revs>.
>
> The Git command line I'm using is:
>     git blame --ignore-revs-file .git-blame-ignore-revs radius.c
>
> Here is an extract where commit 36944f2b16 appears at line 59, though it should be ignored (present in .git-blame-ignore-revs):
>
> 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  50)     int radport;
> 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  51)     char *lochost;
> a9d899ddbe (Russ Allbery       1999-11-29 01:40:47 +0000  52)     int locport;
> 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  53)
> 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  54)     char *prefix, *suffix; /* futz with the username, if necessary */
> 9f21a39f37 (Katsuhiro Kondou   1999-06-12 09:33:48 +0000  55)     int ignore_source;
> d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  56)
> d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  57)     struct _rad_config_t *next; /* point to any additional servers */
> 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  58) } rad_config_t;
> 36944f2b16 (Julien ÉLIE        2021-10-31 10:04:59 +0100  59)
> d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  60) typedef struct _sending_t {
> d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  61)     auth_req req;
> d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  62)     int reqlen;
>
>
> When running git blame without ignoring revisions, commit 36944f2b16 appears at lines 54, 57 and 59:
>
> 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  50)     int radport;
> 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  51)     char *lochost;
> a9d899ddbe (Russ Allbery       1999-11-29 01:40:47 +0000  52)     int locport;
> 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  53)
> 36944f2b16 (Julien ÉLIE        2021-10-31 10:04:59 +0100  54)     char *prefix, *suffix; /* futz with the username, if necessary */
> 9f21a39f37 (Katsuhiro Kondou   1999-06-12 09:33:48 +0000  55)     int ignore_source;
> d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  56)
> 36944f2b16 (Julien ÉLIE        2021-10-31 10:04:59 +0100  57)     struct _rad_config_t *next; /* point to any additional servers */
> 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  58) } rad_config_t;
> 36944f2b16 (Julien ÉLIE        2021-10-31 10:04:59 +0100  59)
> d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  60) typedef struct _sending_t {
> d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  61)     auth_req req;
> d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  62)     int reqlen;
>
>
> Shouldn't 36944f2b16 have disappeared from the output at line 59?
>
> It should have been d65e228465 which already had that line, as it can be seen in the commit (line 53 at that time):
>   https://github.com/InterNetNews/inn/blob/d65e228465700ff044b75aecacb7062d2a1250f9/authprogs/radius.c
>
>
> The result of that command is the same as the one GitHub shows; you can therefore find the whole ouput here:
>
>     https://github.com/InterNetNews/inn/blame/main/authprogs/radius.c
>
> Commit 36944f2b16 is mentioned at lines 59, 129, 144, 293, etc. though present in .git-blame-ignore-revs.
> Yet, that very commit is correctly ignored at other places of the same file.
>
> Other files and other commits in the project are also affected.  I can give more examples if needed.
>
>
> Is it the expected behaviour of "git blame"?
> Is there a reason for these commits to appear in some portions of the blame output?
>
>
> Thanks beforehand,

Michael Platings· Jan 9, 2023, 13:26 UTC · re: Junio C Hamano · lore

Re: Ignored commits appearing in git blame

(Resending. The anti-HTML filter gets me every time) Thanks Junio for forwarding. Hi Julien, You're right, ideally 36944f2b16 should have disappeared from the output at line 5. The way the ignoring algorithm works is that it tries to find a line in the previous commit with similar content. Since there's so little content to compare I guess the algorithm plays it safe and gives up. On the one hand this is annoying because an empty line or single curly brace should be trivial for the algorithm to deal with. On the other hand "which change caused this empty line to be here?" is not a very interesting question so hopefully won't be too much of a problem for you in practice. Thanks for bringing it to my attention. There are a couple of annoyances with the feature I'd like to fix (the main being that there's no way to enable it globally) and I'll add this to the list. However I'm unlikely to get to it soon. I won't complain if you beat me to fixing it :) -Michael

On Mon, 9 Jan 2023 at 04:35, Junio C Hamano <gitster@pobox.com> wrote:

Show 69 quoted lines

>
> Julien ÉLIE <julien@trigofacile.com> writes:
>
> [jc: redirecting to those who touched "blame-ignore" topic in the past]
>
> > Hi all,
> >
> > I'm facing an issue with the use of "git blame" which shows commits marked to be ignored.
> >
> > We have a .git-blame-ignore-revs file that can be retrievable at <https://github.com/InterNetNews/inn/blob/main/.git-blame-ignore-revs>.
> >
> > The Git command line I'm using is:
> >     git blame --ignore-revs-file .git-blame-ignore-revs radius.c
> >
> > Here is an extract where commit 36944f2b16 appears at line 59, though it should be ignored (present in .git-blame-ignore-revs):
> >
> > 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  50)     int radport;
> > 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  51)     char *lochost;
> > a9d899ddbe (Russ Allbery       1999-11-29 01:40:47 +0000  52)     int locport;
> > 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  53)
> > 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  54)     char *prefix, *suffix; /* futz with the username, if necessary */
> > 9f21a39f37 (Katsuhiro Kondou   1999-06-12 09:33:48 +0000  55)     int ignore_source;
> > d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  56)
> > d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  57)     struct _rad_config_t *next; /* point to any additional servers */
> > 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  58) } rad_config_t;
> > 36944f2b16 (Julien ÉLIE        2021-10-31 10:04:59 +0100  59)
> > d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  60) typedef struct _sending_t {
> > d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  61)     auth_req req;
> > d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  62)     int reqlen;
> >
> >
> > When running git blame without ignoring revisions, commit 36944f2b16 appears at lines 54, 57 and 59:
> >
> > 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  50)     int radport;
> > 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  51)     char *lochost;
> > a9d899ddbe (Russ Allbery       1999-11-29 01:40:47 +0000  52)     int locport;
> > 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  53)
> > 36944f2b16 (Julien ÉLIE        2021-10-31 10:04:59 +0100  54)     char *prefix, *suffix; /* futz with the username, if necessary */
> > 9f21a39f37 (Katsuhiro Kondou   1999-06-12 09:33:48 +0000  55)     int ignore_source;
> > d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  56)
> > 36944f2b16 (Julien ÉLIE        2021-10-31 10:04:59 +0100  57)     struct _rad_config_t *next; /* point to any additional servers */
> > 8e3e288fec (Marc G. Fournier   1998-12-29 13:19:05 +0000  58) } rad_config_t;
> > 36944f2b16 (Julien ÉLIE        2021-10-31 10:04:59 +0100  59)
> > d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  60) typedef struct _sending_t {
> > d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  61)     auth_req req;
> > d65e228465 (Jeffrey M. Vinocur 2002-03-14 07:27:00 +0000  62)     int reqlen;
> >
> >
> > Shouldn't 36944f2b16 have disappeared from the output at line 59?
> >
> > It should have been d65e228465 which already had that line, as it can be seen in the commit (line 53 at that time):
> >   https://github.com/InterNetNews/inn/blob/d65e228465700ff044b75aecacb7062d2a1250f9/authprogs/radius.c
> >
> >
> > The result of that command is the same as the one GitHub shows; you can therefore find the whole ouput here:
> >
> >     https://github.com/InterNetNews/inn/blame/main/authprogs/radius.c
> >
> > Commit 36944f2b16 is mentioned at lines 59, 129, 144, 293, etc. though present in .git-blame-ignore-revs.
> > Yet, that very commit is correctly ignored at other places of the same file.
> >
> > Other files and other commits in the project are also affected.  I can give more examples if needed.
> >
> >
> > Is it the expected behaviour of "git blame"?
> > Is there a reason for these commits to appear in some portions of the blame output?
> >
> >
> > Thanks beforehand,

Julien ÉLIE· Jan 10, 2023, 21:09 UTC · re: Michael Platings · lore

Re: Ignored commits appearing in git blame

Hi Michael,

Thanks for having taken time to respond!

Show 5 quoted lines

> You're right, ideally 36944f2b16 should have disappeared from the
> output at line 5. The way the ignoring algorithm works is that it
> tries to find a line in the previous commit with similar content.
> Since there's so little content to compare I guess the algorithm plays
> it safe and gives up.

OK, I understand.

Show 5 quoted lines

> On the one hand this is annoying because an
> empty line or single curly brace should be trivial for the algorithm
> to deal with. On the other hand "which change caused this empty line
> to be here?" is not a very interesting question so hopefully won't be
> too much of a problem for you in practice.

I agree.

Show 5 quoted lines

> There are a couple of
> annoyances with the feature I'd like to fix (the main being that
> there's no way to enable it globally) and I'll add this to the list.
> However I'm unlikely to get to it soon. I won't complain if you beat
> me to fixing it :)

Thanks for having considered the bug report. In case it helps, I've noticed that if I add the "-w" flag (to ignore whitespace in comparisons), the git blame output no longer shows that revision which was asked to be ignored.

   git blame -w --ignore-revs-file .git-blame-ignore-revs radius.c

I don't know whether it is a coincidence (especially when .git-blame-ignore-revs contains in fact commits of code reformatting and whitespace cleaning) or it would also help for other kind of commits to ignore.

-- 
Julien ÉLIE

« Le bonheur, c'est de continuer à désirer ce que l'on possède. »
   (Saint-Augustin)