Re: [Breakage] Git v2.21.0-rc0 - t5318 (NonStop)

From: Johannes Sixt <j6t@kdbg.org>
Date: Feb 8, 2019, 18:29 UTC
Message-ID: <0694f2f1-040a-1d8c-cd01-2cf51cdbe426@kdbg.org>
In-Reply-To: <20190208180321.GB27673@sigill.intra.peff.net>

Am 08.02.19 um 19:03 schrieb Jeff King:

Show 20 quoted lines

> On Fri, Feb 08, 2019 at 12:49:59PM -0500, Randall S. Becker wrote:
>> Would you object to something like this:
>>
>> if [ ! -e /dev/zero ]; then
>> 	# use shred or some other mechanism (still trying to figure out a solution)
>> else
>> 	# existing dd
>> fi
> 
> That's fine, as long as it's wrapped up in a function in order to keep
> the tests readable.
> 
> Though I suspect we may be able to just find a solution that works
> everywhere, without having two different implementations. If we know we
> need $count bytes for dd, we could probably just generate a file with
> that many NULs in it.
> 
> Other cases don't seem to actually care that they're getting NULs, and
> are just redirecting stdin from /dev/zero to get an infinite amount of
> input. They could probably use "yes" for that.

If the data does not have to be a sequence of zero bytes, the alternatives are:

* `test-genrandom seed-string $size` for a sequence of reproducible
"random" bytes

* `printf "%0*d" $size 0` for a sequence of '0' characters.

In t5318, the zero bytes do matter, though.

-- Hannes