[0/5] diff output_prefix cleanups

Message

Jeff King Oct. 3, 2024, 9:05 p.m. UTC

On Thu, Oct 03, 2024 at 11:58:41AM +0000, Derrick Stolee via GitGitGadget wrote:

> This fixes a regression introduced in 2.46.0.
> 
> The change made in 394affd46d (line-log: always allocate the output prefix,
> 2024-06-07) made the method more consistent in that it did not return a
> static empty string that would fail to free(), but it does lead to
> double-frees when a strbuf buffer is freed multiple times.
> 
> In v2, I add Peff's test to the first patch. I also split his diff into two
> more follow-up patches because the additional clarity seems valuable to me.
> I have forged his sign-off in all three patches.
> 
> Note to the maintainer: feel free to take only the first patch, as Peff
> replied that he may work on the remaining cleanup independently (but I had
> already prepared patches 2 & 3).

Oh, I wasn't expecting you to go to that trouble, and had already
polished them up myself. :)

So certainly your patch 1 looks good to me now. Here's what I would
put on top (but I would suggest making it a separate branch, since yours
is a fairly urgent fix and mine is all cleanup).

  [1/5]: line-log: use diff_line_prefix() instead of custom helper
  [2/5]: diff: drop line_prefix_length field
  [3/5]: diff: return const char from output_prefix callback
  [4/5]: diff: return line_prefix directly when possible
  [5/5]: diff: store graph prefix buf in git_graph struct

 diff-lib.c   |  4 ++--
 diff.c       | 10 +++-------
 diff.h       |  3 +--
 graph.c      | 29 +++++++++++++++++------------
 line-log.c   | 14 ++------------
 log-tree.c   |  7 +------
 range-diff.c |  4 ++--
 7 files changed, 28 insertions(+), 43 deletions(-)

-Peff

Comments

Derrick Stolee Oct. 4, 2024, 7:27 p.m. UTC | #1

On 10/3/24 5:05 PM, Jeff King wrote:
> On Thu, Oct 03, 2024 at 11:58:41AM +0000, Derrick Stolee via GitGitGadget wrote:

>> Note to the maintainer: feel free to take only the first patch, as Peff
>> replied that he may work on the remaining cleanup independently (but I had
>> already prepared patches 2 & 3).
> 
> Oh, I wasn't expecting you to go to that trouble, and had already
> polished them up myself. :)

It's perfectly fine that we were attempting to save each other work.

> So certainly your patch 1 looks good to me now. Here's what I would
> put on top (but I would suggest making it a separate branch, since yours
> is a fairly urgent fix and mine is all cleanup).

I approve of this plan. Please only consider my first patch and drop
the others.

Thanks,
-Stolee

Junio C Hamano Oct. 4, 2024, 7:31 p.m. UTC | #2

Derrick Stolee <[e-mail]> writes:

> On 10/3/24 5:05 PM, Jeff King wrote:
>> On Thu, Oct 03, 2024 at 11:58:41AM +0000, Derrick Stolee via GitGitGadget wrote:
>
>>> Note to the maintainer: feel free to take only the first patch, as Peff
>>> replied that he may work on the remaining cleanup independently (but I had
>>> already prepared patches 2 & 3).
>> Oh, I wasn't expecting you to go to that trouble, and had already
>> polished them up myself. :)
>
> It's perfectly fine that we were attempting to save each other work.
>
>> So certainly your patch 1 looks good to me now. Here's what I would
>> put on top (but I would suggest making it a separate branch, since yours
>> is a fairly urgent fix and mine is all cleanup).
>
> I approve of this plan. Please only consider my first patch and drop
> the others.

Yup.  Thanks, both.  The result looked very sensible.

Derrick Stolee Oct. 4, 2024, 7:33 p.m. UTC | #3

On 10/3/24 5:05 PM, Jeff King wrote:
 > Here's what I would> put on top (but I would suggest making it a separate 
branch, since yours
> is a fairly urgent fix and mine is all cleanup).
> 
>    [1/5]: line-log: use diff_line_prefix() instead of custom helper
>    [2/5]: diff: drop line_prefix_length field
>    [3/5]: diff: return const char from output_prefix callback
>    [4/5]: diff: return line_prefix directly when possible
>    [5/5]: diff: store graph prefix buf in git_graph struct

I've reviewed these patches and they look good to me. Thanks for
taking the time to split them up carefully to help review go so
smoothly.

>   7 files changed, 28 insertions(+), 43 deletions(-)

Excellent to see the line reduction, too.

Thanks,
-Stolee