Re: [Patch v1 3/3] t5562: replace /dev/zero with a pipe from generate_zero_bytes

[Junio C Hamano <gitster@pobox.com>]

Eric Sunshine <sunshine@sunshineco.com> writes:

[jc: Summoning Dscho, J6t for their Windows expertise at the end]

> On Sat, Feb 9, 2019 at 1:59 PM <randall.s.becker@rogers.com> wrote:
>> This change removes the dependency on /dev/zero with an equivalent  pipe of
>
> Too many spaces between "equivalent" and "pipe".
>
>> deliberately NUL bytes. This allows tests to proceed where /dev/zero
>> does not exist.
>
> It wouldn't hurt to cite "NonStop" as an example of a platform lacking
> /dev/zero.
>
> The first sentence is a bit off grammatically. Perhaps the entire
> commit message can be collapsed simply to:
>
>     Stop depending on /dev/zero which may not be available on all
>     platforms (for instance, HP NonStop).
>
>> Signed-off-by: Randall S. Becker <rsbecker@nexbridge.com>
>> ---
>> diff --git a/t/t5562-http-backend-content-length.sh b/t/t5562-http-backend-content-length.sh
>> @@ -143,14 +143,14 @@ test_expect_success GZIP 'push gzipped empty' '
>>  test_expect_success 'CONTENT_LENGTH overflow ssite_t' '
>>         NOT_FIT_IN_SSIZE=$(ssize_b100dots) &&
>> -       env \
>> +       generate_zero_bytes infinity  | env \
>>                 CONTENT_TYPE=application/x-git-upload-pack-request \
>>                 QUERY_STRING=/repo.git/git-upload-pack \
>>                 PATH_TRANSLATED="$PWD"/.git/git-upload-pack \
>>                 GIT_HTTP_EXPORT_ALL=TRUE \
>>                 REQUEST_METHOD=POST \
>>                 CONTENT_LENGTH="$NOT_FIT_IN_SSIZE" \
>> -               git http-backend </dev/zero >/dev/null 2>err &&
>> +               git http-backend >/dev/null 2>err &&

Doesn't this "inifinity" mode have the same issue that was worked
around by 6129c930 ("test-lib: limit the output of the yes utility",
2016-02-02) on Windows?  If I read correctly, the process upstream
of the pipe (in this case, perl producing a stream of infinite NULs)
would not die when the downstream stops reading with SIGPIPE.

Or is it safe to assume that nobody expects to use http-backend on
Windows based servers so this test is a non-issue?

>>         grep "fatal:.*CONTENT_LENGTH" err
>>  '

Thanks.