Re: [PATCH] upload-pack: fix race condition in error messages

> To reduce the risk of this failure, follow this process instead:
>
> 1. Write an error message to stderr.
> 2. Write an error message across the connection.
> 3. exit(1).
>
> This reorders the events so the error is written entirely before
> the client receives a message from the remote, removing the race
> condition.

> Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
> ---
>     upload-pack: fix race condition in error messages
>     
>     Here is another quick patch that we've been holding in the microsoft/git
>     fork for years because it helped prevent some test flakiness, especially
>     in our more involved functional test environment.
>     
>     Thanks, -Stolee
>
> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1572%2Fderrickstolee%2Fupload-pack-race-v1
> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1572/derrickstolee/upload-pack-race-v1
> Pull-Request: https://github.com/gitgitgadget/git/pull/1572
>
>  upload-pack.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/upload-pack.c b/upload-pack.c
> index 94751477ab2..7b25129f0f6 100644
> --- a/upload-pack.c
> +++ b/upload-pack.c
> @@ -801,11 +801,12 @@ error:
>  	for (i = 0; i < data->want_obj.nr; i++) {
>  		struct object *o = data->want_obj.objects[i].item;
>  		if (!is_our_ref(o, data->allow_uor)) {
> +			error("git upload-pack: not our ref %s",
> +			      oid_to_hex(&o->oid));
>  			packet_writer_error(&data->writer,
>  					    "upload-pack: not our ref %s",
>  					    oid_to_hex(&o->oid));
> -			die("git upload-pack: not our ref %s",
> -			    oid_to_hex(&o->oid));
> +			exit(1);
>  		}
>  	}
>  }
>
> base-commit: a82fb66fed250e16d3010c75404503bea3f0ab61