threads / patch / 61108

patchlog: make the --oneline option work with -L

Subject: [PATCH 0/1] log: make the --oneline option work with -L

## tl;dr

7 messages between Mar 13, 2024 and Mar 13, 2024. Diffs are folded; open one to read it.

replies: 6people: 3as markdown or json

James Liu· Mar 13, 2024, 09:08 UTC · lore

Hey folks,

This is a small patch to fix an issue I've experienced with git-log(1) when certain combinations of flags are provided. This is also my very first patch submission, so I've tried to limit the blast radius as much as possible. I'm also unsure if this is the best place to implement the change, so any feedback is welcome!

I'd like to ideally add a test as well, but I'm unsure where this should slot in.

git-log accepts the --oneline option to display the short commit SHA and title only. This is a convenient option when searching through Git history, as it gives a rough idea of the changes introduced in each commit. git-log also accepts the -L flag, which lets us provide a line range for a given file. This is handy for limiting the search to a given area of interest.

However, when --oneline is used in combination with -L, Git actually outputs the single line commit information _as well_ as the full diff. For example:

        git log --oneline -L 660:Documentation/MyFirstObjectWalk.txt

will incorrectly display the diffs too.

This patch aims to fix this behaviour by respecting the --oneline option when used in conjunction with -L.

James Liu (1):
  log: ensure diffs are omitted with --oneline

 builtin/log.c | 4 ++++
 1 file changed, 4 insertions(+)

-- 
2.43.2

James Liu· Mar 13, 2024, 09:08 UTC · re: James Liu · lore

[PATCH 1/1] log: ensure diffs are omitted with --oneline

Currently when `git log --oneline` is invoked with the -L flag, the full diffs are displayed along with the single line commit message. It appears that within the log_tree_commit() function, the special case that executes when opt->line_level_traverse is enabled (as in the case when -L is provided) doesn't respect the --oneline option.

Ensure the --oneline option is respected by explicitly setting DIFF_FORMAT_NO_OUTPUT if required.

Signed-off-by: James Liu <james@jamesliu.io>
---
 builtin/log.c | 4 ++++
 1 file changed, 4 insertions(+)

Show changes to builtin/log.c +4 −0

diff --git a/builtin/log.c b/builtin/log.c
index e5da0d1043..dd77ede00c 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -279,6 +279,10 @@ static void cmd_log_init_finish(int argc, const char **argv, const char *prefix,
 		rev->diffopt.output_format |= DIFF_FORMAT_NO_OUTPUT;
 	argc = setup_revisions(argc, argv, rev, opt);
 
+	/* Ensure that we don't output diffs if the --oneline flag is provided */
+	if (rev->commit_format == CMIT_FMT_ONELINE)
+		rev->diffopt.output_format |= DIFF_FORMAT_NO_OUTPUT;
+
 	/* Any arguments at this point are not recognized */
 	if (argc > 1)
 		die(_("unrecognized argument: %s"), argv[1]);

-- 
2.43.2

Junio C Hamano· Mar 13, 2024, 17:31 UTC · re: James Liu · lore

Re: [PATCH 0/1] log: make the --oneline option work with -L

James Liu <james@jamesliu.io> writes:

Show 14 quoted lines

> git-log accepts the --oneline option to display the short commit SHA and
> title only. This is a convenient option when searching through Git
> history, as it gives a rough idea of the changes introduced in each
> commit. git-log also accepts the -L flag, which lets us provide a line
> range for a given file. This is handy for limiting the search to a given
> area of interest.
>
> However, when --oneline is used in combination with -L, Git actually
> outputs the single line commit information _as well_ as the full diff.
> For example:
>
>         git log --oneline -L 660:Documentation/MyFirstObjectWalk.txt
>
> will incorrectly display the diffs too.

Why is it incorrect?

 * "git log" takes options to tweak formatting of the commit log,
   options to tweak what commits are chosen, and options to tweak
   how the diff are shown.

 * "--oneline" tweaks how the log message gets shown.  Others in the
   family are --pretty=fuller, --format='%h %s', etc.

 * "-L" tweaks how the diff gets shown (e.g. limits which part of
   the diff is shown) and what commits are shown (e.g. limits to
   commits that touch the specified area).

So, just like "git log -L <range>:<file>" shows the commit log for each commit that touches the specified area of the file, followed by the diff that shows how the commit modified the range, it is natural to expect "git log --oneline -L <range>:<file>" to show the same diff after showing the commit log for these commits in the specified format, namely, with just a one-line description.

It is not limited to "-L"; "git log --oneline -p" is expected to show the patch after a one-line description for the commit.

Beat Bolli· Mar 13, 2024, 18:08 UTC · re: Junio C Hamano · lore

Re: [PATCH 0/1] log: make the --oneline option work with -L

On 13.03.24 18:31, Junio C Hamano wrote:

Show 40 quoted lines

> James Liu <james@jamesliu.io> writes:
> 
>> git-log accepts the --oneline option to display the short commit SHA and
>> title only. This is a convenient option when searching through Git
>> history, as it gives a rough idea of the changes introduced in each
>> commit. git-log also accepts the -L flag, which lets us provide a line
>> range for a given file. This is handy for limiting the search to a given
>> area of interest.
>>
>> However, when --oneline is used in combination with -L, Git actually
>> outputs the single line commit information _as well_ as the full diff.
>> For example:
>>
>>          git log --oneline -L 660:Documentation/MyFirstObjectWalk.txt
>>
>> will incorrectly display the diffs too.
> 
> Why is it incorrect?
> 
>   * "git log" takes options to tweak formatting of the commit log,
>     options to tweak what commits are chosen, and options to tweak
>     how the diff are shown.
> 
>   * "--oneline" tweaks how the log message gets shown.  Others in the
>     family are --pretty=fuller, --format='%h %s', etc.
> 
>   * "-L" tweaks how the diff gets shown (e.g. limits which part of
>     the diff is shown) and what commits are shown (e.g. limits to
>     commits that touch the specified area).
> 
> So, just like "git log -L <range>:<file>" shows the commit log for
> each commit that touches the specified area of the file, followed by
> the diff that shows how the commit modified the range, it is natural
> to expect "git log --oneline -L <range>:<file>" to show the same diff
> after showing the commit log for these commits in the specified format,
> namely, with just a one-line description.
> 
> It is not limited to "-L"; "git log --oneline -p" is expected to
> show the patch after a one-line description for the commit.
>

There's also "--no-patch" to suppress the patch. It combines well with "--oneline".

-- 
Cheers, Beat

James Liu· Mar 13, 2024, 22:25 UTC · re: Beat Bolli · lore

Re: [PATCH 0/1] log: make the --oneline option work with -L

On Thu Mar 14, 2024 at 5:08 AM AEDT, Beat Bolli wrote:

> There's also "--no-patch" to suppress the patch. It combines well with 
> "--oneline".

Thanks! That's a good one to keep handy.

James Liu· Mar 13, 2024, 22:24 UTC · re: Junio C Hamano · lore

Re: [PATCH 0/1] log: make the --oneline option work with -L

On Thu Mar 14, 2024 at 4:31 AM AEDT, Junio C Hamano wrote:

Show 22 quoted lines

> James Liu <james@jamesliu.io> writes:
>
> > However, when --oneline is used in combination with -L, Git actually
> > outputs the single line commit information _as well_ as the full diff.
> > For example:
> >
> >         git log --oneline -L 660:Documentation/MyFirstObjectWalk.txt
> >
> > will incorrectly display the diffs too.
>
> Why is it incorrect?
>
>  * "git log" takes options to tweak formatting of the commit log,
>    options to tweak what commits are chosen, and options to tweak
>    how the diff are shown.
>
>  * "--oneline" tweaks how the log message gets shown.  Others in the
>    family are --pretty=fuller, --format='%h %s', etc.
>
>  * "-L" tweaks how the diff gets shown (e.g. limits which part of
>    the diff is shown) and what commits are shown (e.g. limits to
>    commits that touch the specified area).

I suppose it isn't intuitive to me which options affect how the commits are presented, and which affect the diffs. The help entry for -L states that it will "Trace the evolution of the line range", which doesn't immediately suggest that it tweaks how the log message is shown. As a user of this option, I'm more interested in using it as a filter for how commits are chosen.

-S feels like a similar option to -L, but will omit the diff when used with --oneline. I think I was probably experimenting with "--oneline -S" and then was surprised to see diffs after trying "--oneline -L".

Junio C Hamano· Mar 13, 2024, 22:47 UTC · re: James Liu · lore

Re: [PATCH 0/1] log: make the --oneline option work with -L

"James Liu" <james@jamesliu.io> writes:

> I suppose it isn't intuitive to me which options affect how the commits
> are presented, and which affect the diffs. The help entry for -L states
> that it will "Trace the evolution of the line range", which doesn't
> immediately suggest that it tweaks how the log message is shown.

Sorry, but you lost me.  I do not understand this remark.

The documentation for "-L" does not talk about tweaking how the message is shown at all, because "-L" does not have a say in how the log message gets shown at all. And the documentation for "--oneline", "--format", "--pretty" all should talk about how the log message gets shown.

Anyway, if you are happy with "--no-patch", that's good.