Re: [PATCH 0/2] Graph horizontal fix

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 8, 2020, 18:06 UTC
Message-ID: <xmqq5zhl3jrm.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <pull.518.git.1578457675.gitgitgadget@gmail.com>

"Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com> writes:

Show 16 quoted lines

> This depends on ds/graph-assert-fix.
>
> This is a non-critical (not needed for v2.25.0) response to the previous
> discussions [1] [2].
>
> While working to resolve the fix for the assert() bug, I noticed this
> regression when multiple edges wanted to collapse with horizontal lines. It
> takes a reasonably large graph, but real projects are likely to demonstrate
> this behavior.
>
> I arranged the series into two patches: 1. the (failing) test, and 2. the
> fix.
>
> The fix commit includes some details about why the change to compress merge
> commits caused this regression, and why I feel relatively confident that
> this is a correct resolution.

I am not sure if this is "fix" of "bug" in that what is shown without 2/2 (iow, "before this change" in the description of 2/2) is "wrong" per-se---it is just that it leaves room to be made even more compact. It still is an improvement, of course, though.

Queued.  Thanks.

Show 21 quoted lines

>
> Thanks, -Stolee
>
> [1] 
> https://lore.kernel.org/git/faa954fa-ccb9-b034-a39d-d2f0696826ea@gmail.com/T/#t
> [2] 
> https://lore.kernel.org/git/xmqqk1635gwu.fsf@gitster-ct.c.googlers.com/T/#t
>
> Derrick Stolee (2):
>   graph: add test to demonstrate horizontal line bug
>   graph: fix collapse of multiple edges
>
>  graph.c                      | 10 ++++--
>  t/t4215-log-skewed-merges.sh | 62 ++++++++++++++++++++++++++++++++++++
>  2 files changed, 70 insertions(+), 2 deletions(-)
>
>
> base-commit: aa2121af50498c7ea9d5c4c87f9dc66605bf772b
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-518%2Fderrickstolee%2Fgraph-horizontal-fix-v1
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-518/derrickstolee/graph-horizontal-fix-v1
> Pull-Request: https://github.com/gitgitgadget/git/pull/518