'git log --source' seems to fail to show ref name after the first tag comes out.

'git log --source' seems to fail to show ref name after the first tag comes out.

[Raymundo]

Hello,

At first, I'm sorry I'm not good at English.


When I execute this command:

git log --oneline --source --all --decorate

I get the output below: (I replaced commit messages written in Korean
with "COMMIT MSG")

295c670 refs/heads/gyparkwiki_base (gyparkwiki_base) COMMIT MSG
c130d61 refs/heads/master (HEAD -> master, origin/master, origin/HEAD)
version 2.27a
6f6f40c refs/heads/gyparkwiki (gyparkwiki) COMMIT MSG
...
a37772f refs/heads/gyparkwiki COMMIT MSG
afeaa51 refs/heads/gyparkwiki COMMIT MSG
af2676e  (tag: last_CVS_utf) COMMIT MSG   <- ref name is not shown
from this line
b4d27c9  COMMIT MSG
4f834f8  COMMIT MSG
...
7534d49  COMMIT MSG
e5c8a6c  *** empty log message ***
596aa3e refs/tags/urlprefix (tag: urlprefix) COMMIT MSG  <- ref name
appears again from this line
8fc4de3 refs/tags/urlprefix COMMIT MSG
...
a0b587 refs/tags/urlprefix COMMIT MSG
f8526f9 refs/tags/urlprefix COMMIT MSG
277478b  (tag: last_CVS_testwiki) COMMIT MSG <- ref name disappear
again from this line
65919c8  *** empty log message ***
...

As you can see, ref names in the second column repeats to disappear
and come back, at every lines that contain tags.

I tested using Git version 2.6.3

For reference, Git version 1.7.9.rc0 does not have this problem. It
shows ref names on all lines well.


Maybe is this a bug?

Thank you.
G.Y.Park from South Korea

Re: 'git log --source' seems to fail to show ref name after the first tag comes out.

[Jeff King]

On Wed, Nov 25, 2015 at 07:29:02PM +0900, Raymundo wrote:

> At first, I'm sorry I'm not good at English.

No problem. Your report was very clear. :)

> When I execute this command:
> 
> git log --oneline --source --all --decorate
> [...]
> As you can see, ref names in the second column repeats to disappear
> and come back, at every lines that contain tags.

I was able to reproduce this pretty easily with a short test case:

  git init
  git commit --allow-empty -m one
  git commit --allow-empty -m two
  git commit --allow-empty -m three
  git tag -m mytag HEAD^

Starting from one source works:

  $ git log --oneline --source master
  de009a4 master three
  b75220d master two
  62f49bd master one

But starting from the tag as well does not:

  $ git log --oneline --source master mytag
  de009a4 master three
  b75220d  two
  62f49bd  one

Or more simply, starting from the tag never has any sources:

  $ git log --oneline --source mytag
  b75220d  two
  62f49bd  one

It's like the tag paints its commit with an empty "source" field (and
then we propagate that down the graph).

> I tested using Git version 2.6.3
> 
> For reference, Git version 1.7.9.rc0 does not have this problem. It
> shows ref names on all lines well.

Sounds like a good opportunity to use git-bisect. I came up with 2073949
(traverse_commit_list: support pending blobs/trees with paths,
2014-10-15) from git v2.2.0, which unfortunately was written by me. :)

This one-liner seems to fix it:

diff --git a/revision.c b/revision.c
index af2a18e..d434b8b 100644
--- a/revision.c
+++ b/revision.c
@@ -297,7 +297,6 @@ static struct commit *handle_commit(struct rev_info *revs,
 		 * through to the non-tag handlers below. Do not
 		 * propagate data from the tag's pending entry.
 		 */
-		name = "";
 		path = NULL;
 		mode = 0;
 	}

But I'm not sure if it causes other problems. In particular, I see why
we would not propagate a path field, but I do not know why the original
was avoiding propagating the name field.

-Peff

Re: 'git log --source' seems to fail to show ref name after the first tag comes out.

[Raymundo]

2015-11-25 21:59 GMT+09:00 Jeff King <peff@peff.net>:
>
> Sounds like a good opportunity to use git-bisect. I came up with 2073949
> (traverse_commit_list: support pending blobs/trees with paths,
> 2014-10-15) from git v2.2.0, which unfortunately was written by me. :)
>
> This one-liner seems to fix it:
>
> diff --git a/revision.c b/revision.c
> index af2a18e..d434b8b 100644
> --- a/revision.c
> +++ b/revision.c
> @@ -297,7 +297,6 @@ static struct commit *handle_commit(struct rev_info *revs,
>                  * through to the non-tag handlers below. Do not
>                  * propagate data from the tag's pending entry.
>                  */
> -               name = "";
>                 path = NULL;
>                 mode = 0;
>         }
>
> But I'm not sure if it causes other problems. In particular, I see why
> we would not propagate a path field, but I do not know why the original
> was avoiding propagating the name field.
>
> -Peff

It's a good news that you found the reason so soon.

I'd like to wait for next version :-)

Thank you!