GNU bug report logs - #67593
`split --number=l/N` no longer splits evenly

Please note: This is a static page, with minimal formatting, updated once a day.
Click here to see this page with the latest information and nicer formatting.
Package: coreutils; Reported by: Victor Engmark <victor@HIDDEN>; Keywords: notabug; dated Sun, 3 Dec 2023 00:26:01 UTC; Maintainer for coreutils is bug-coreutils@HIDDEN.
Added tag(s) notabug. Request was from Paul Eggert <eggert@HIDDEN> to control <at> debbugs.gnu.org. Full text available.

Message received at 67593 <at> debbugs.gnu.org:


Received: (at 67593) by debbugs.gnu.org; 3 Dec 2023 09:38:00 +0000
From debbugs-submit-bounces <at> debbugs.gnu.org Sun Dec 03 04:38:00 2023
Received: from localhost ([127.0.0.1]:59141 helo=debbugs.gnu.org)
	by debbugs.gnu.org with esmtp (Exim 4.84_2)
	(envelope-from <debbugs-submit-bounces <at> debbugs.gnu.org>)
	id 1r9ivH-0005E2-NZ
	for submit <at> debbugs.gnu.org; Sun, 03 Dec 2023 04:38:00 -0500
Received: from mail.cs.ucla.edu ([131.179.128.66]:43494)
 by debbugs.gnu.org with esmtp (Exim 4.84_2)
 (envelope-from <eggert@HIDDEN>) id 1r9ivC-0005Dl-HH
 for 67593 <at> debbugs.gnu.org; Sun, 03 Dec 2023 04:37:58 -0500
Received: from localhost (localhost [127.0.0.1])
 by mail.cs.ucla.edu (Postfix) with ESMTP id A0D013C011BE8;
 Sun,  3 Dec 2023 01:37:38 -0800 (PST)
Received: from mail.cs.ucla.edu ([127.0.0.1])
 by localhost (mail.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032)
 with ESMTP id FGWrLZ70_9Dl; Sun,  3 Dec 2023 01:37:38 -0800 (PST)
Received: from localhost (localhost [127.0.0.1])
 by mail.cs.ucla.edu (Postfix) with ESMTP id 40B763C011BE9;
 Sun,  3 Dec 2023 01:37:38 -0800 (PST)
DKIM-Filter: OpenDKIM Filter v2.10.3 mail.cs.ucla.edu 40B763C011BE9
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cs.ucla.edu;
 s=9D0B346E-2AEB-11ED-9476-E14B719DCE6C; t=1701596258;
 bh=aDy4ky4M39t5F1qmqyh0WFciUApGhm4yUPUGUs/kRCI=;
 h=Message-ID:Date:MIME-Version:To:From;
 b=hgFsC+Dvndau/kIARzwGzlQirgAi0KOipLQNLngi30r0px2z/BSdPsRPHnYV6Dn3L
 VBTmduCuREeooEXcixJ841T2oiAF4nKh9by/qSkhftSbi+bCZdBU2JtqV5KXEb4izj
 gIfaK3Zq3A8y22wMbTw7G9bPyNXGNidJMDvsBrphEWMJS47z4bZwpM+/UYJhc5KgPp
 /e8Jwn66HuOmP7p0lpyw8kEvGtc6JnEO00mdqrOE0nnosdNKTWozwI7Sg1RlaJD1cM
 U+gyv+mFzXigGOKlAgA9PC6+krQvezmAUIMeYebzBhxUzOKs2n7yqYZsEr2hzxA0U+
 l6GXbr/tFXlig==
X-Virus-Scanned: amavisd-new at mail.cs.ucla.edu
Received: from mail.cs.ucla.edu ([127.0.0.1])
 by localhost (mail.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026)
 with ESMTP id eubgGxeoDxLg; Sun,  3 Dec 2023 01:37:38 -0800 (PST)
Received: from [192.168.254.12] (unknown [47.148.192.211])
 by mail.cs.ucla.edu (Postfix) with ESMTPSA id 197003C011BE8;
 Sun,  3 Dec 2023 01:37:38 -0800 (PST)
Message-ID: <fd60967a-6dd1-4f38-98fb-e253c64a40a0@HIDDEN>
Date: Sun, 3 Dec 2023 01:37:37 -0800
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: bug#67593: `split --number=l/N` no longer splits evenly
Content-Language: en-US
To: Victor Engmark <victor@HIDDEN>
References: <e965589eeb832a95c0d107345244e928f57f060d.camel@HIDDEN>
From: Paul Eggert <eggert@HIDDEN>
Organization: UCLA Computer Science Department
In-Reply-To: <e965589eeb832a95c0d107345244e928f57f060d.camel@HIDDEN>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
X-Spam-Score: -0.0 (/)
X-Debbugs-Envelope-To: 67593
Cc: 67593 <at> debbugs.gnu.org
X-BeenThere: debbugs-submit <at> debbugs.gnu.org
X-Mailman-Version: 2.1.18
Precedence: list
List-Id: <debbugs-submit.debbugs.gnu.org>
List-Unsubscribe: <https://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>, 
 <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe>
List-Archive: <https://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/>
List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org>
List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help>
List-Subscribe: <https://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>, 
 <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe>
Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org
Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org>
X-Spam-Score: -1.0 (-)

That's not a bug, in that 'split' is behaving as documented. The first 
input line is one byte shorter than the second one. 'Split' divides the 
input into two regions, and because the first region happens to be one 
byte longer than the second region both input lines are sent to the 
first output file.

In older coreutils, 'split' used a different algorithm to compute region 
sizes, which worked better for your test case but considerably worse in 
others. For example, in older coreutils:

seq 50 >in
split -n l/71 in

created 43 files of size 0, 9 files of size 2, 18 files of size 3, and 
one file of size 69. Current coreutils splits much better: it creates 21 
files of size 0, 9 files of size 2, and 41 files of size 3.
Information forwarded to bug-coreutils@HIDDEN:
bug#67593; Package coreutils. Full text available.

Message received at submit <at> debbugs.gnu.org:


Received: (at submit) by debbugs.gnu.org; 3 Dec 2023 00:25:42 +0000
From debbugs-submit-bounces <at> debbugs.gnu.org Sat Dec 02 19:25:42 2023
Received: from localhost ([127.0.0.1]:58911 helo=debbugs.gnu.org)
	by debbugs.gnu.org with esmtp (Exim 4.84_2)
	(envelope-from <debbugs-submit-bounces <at> debbugs.gnu.org>)
	id 1r9aIo-00053o-DG
	for submit <at> debbugs.gnu.org; Sat, 02 Dec 2023 19:25:42 -0500
Received: from lists.gnu.org ([2001:470:142::17]:40304)
 by debbugs.gnu.org with esmtp (Exim 4.84_2)
 (envelope-from <victor@HIDDEN>) id 1r9aIm-00053Z-Pe
 for submit <at> debbugs.gnu.org; Sat, 02 Dec 2023 19:25:41 -0500
Received: from eggs.gnu.org ([2001:470:142:3::10])
 by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
 (Exim 4.90_1) (envelope-from <victor@HIDDEN>)
 id 1r9aIV-0005lH-Dh
 for bug-coreutils@HIDDEN; Sat, 02 Dec 2023 19:25:23 -0500
Received: from smtp.domeneshop.no ([2a01:5b40:0:3006::1])
 by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
 (Exim 4.90_1) (envelope-from <victor@HIDDEN>)
 id 1r9aIN-0005aZ-NO
 for bug-coreutils@HIDDEN; Sat, 02 Dec 2023 19:25:22 -0500
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed;
 d=engmark.name; s=ds202212; h=MIME-Version:Content-Transfer-Encoding:
 Content-Type:Date:To:From:Subject:Message-ID:Sender:Reply-To:Cc:Content-ID:
 Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc
 :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:
 List-Subscribe:List-Post:List-Owner:List-Archive;
 bh=O1iFrUJFvDV263dpvBIsk8p82GVI3aX03eIalu3VeBU=; b=E0+YELAD7wSJRC/kSJj40Pt6sz
 6agORx+rcAn7HYMhNDxIzYXSm5nYu2EImhyZscJQYgy3BkcZk9ro/YEchoCY65HxCPBfcwbKydMZj
 Na33442g4UEQ+FVVCBE3hEDioNH6Ki8cmrxrAtZ8Pz/rFO90TYT4p8ZLkon6fx3tcswQsGYE6VI5X
 n/636l+7lyyzHW/eezEMJeHIQZLl8Op+7w0VKUqbYyK1hGjiqchzVxxAr7Z7PDTbfot46jJ1HysL5
 vk06U+SVBx/rX0lg/lBcROiBulousnfD1US29pOGjtcPc+mWjgkNHZZI7+ES5vLeTTX+oJ1eLgYCH
 L82HKW+Q==;
Received: from [2404:440c:2302:a500:2f69:6958:165a:f3b4] (port=46542
 helo=default-rdns.vocus.co.nz)
 by smtp.domeneshop.no with esmtpsa (TLS1.3) tls
 TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95)
 (envelope-from <victor@HIDDEN>) id 1r9aID-001pUa-UY
 for bug-coreutils@HIDDEN; Sun, 03 Dec 2023 01:25:06 +0100
Message-ID: <e965589eeb832a95c0d107345244e928f57f060d.camel@HIDDEN>
Subject: `split --number=l/N` no longer splits evenly
From: Victor Engmark <victor@HIDDEN>
To: bug-coreutils@HIDDEN
Date: Sun, 03 Dec 2023 13:25:01 +1300
Autocrypt: addr=victor@HIDDEN; prefer-encrypt=mutual;
 keydata=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
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
User-Agent: Evolution 3.50.1 
MIME-Version: 1.0
Received-SPF: pass client-ip=2a01:5b40:0:3006::1;
 envelope-from=victor@HIDDEN; helo=smtp.domeneshop.no
X-Spam_score_int: -20
X-Spam_score: -2.1
X-Spam_bar: --
X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1,
 DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_PASS=-0.001,
 SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no
X-Spam_action: no action
X-Spam-Score: 1.0 (+)
X-Debbugs-Envelope-To: submit
X-BeenThere: debbugs-submit <at> debbugs.gnu.org
X-Mailman-Version: 2.1.18
Precedence: list
List-Id: <debbugs-submit.debbugs.gnu.org>
List-Unsubscribe: <https://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>, 
 <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe>
List-Archive: <https://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/>
List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org>
List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help>
List-Subscribe: <https://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>, 
 <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe>
Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org
Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org>
X-Spam-Score: -0.0 (/)

Hi all

Commit fb6fc7f3ce6b0b70a5df7f605e71c4f8541e256b (part of v9.2)
introduced a regression in how `split --number=3Dl/N` works.

Test script `tests/split/l-chunk2.sh`:

```
#!/bin/sh

. "${srcdir=3D.}/tests/init.sh"; path_prepend_ ./src
print_ver_ split

printf 'first\n' > exp1 || framework_failure_
printf 'second\n' > exp2 || framework_failure_
cat exp1 exp2 > in || framework_failure_
split -e -n l/2 in || framework_failure_
compare exp1 xaa || fail=3D1
compare exp2 xab || fail=3D1

Exit $fail
```

Relevant test output:

```
+ diff -u exp1 xaa
--- exp1	2023-12-03 12:42:50.511334991 +1300
+++ xaa	2023-12-03 12:42:50.513334908 +1300
@@ -1 +1,2 @@
 first
+second
```

and

```
+ diff -u exp2 xab
diff: xab: No such file or directory
```

In other words, it doesn't split the file at all, despite it containing
two lines of content.

The bug is still present in current master (commit
73d119f4f8052a9fb6cef13cd9e75d5a4e23311a).

Bisected on NixOS 23.11 using the following script:

```
#!/bin/sh

set -e

export CFLAGS=3D-w # Avoid build failure

git submodule update
git clean -fdx --exclude=3Dbisect.sh --exclude=3Dtests/split/l-chunk2.sh

./bootstrap
autoconf
./configure
make
make check TESTS=3Dtests/split/l-chunk2.sh SUBDIRS=3D.
```

and these commands:

```
git bisect start master v9.1
git bisect run ./bisect.sh
```

Cheers
Victor
Acknowledgement sent to Victor Engmark <victor@HIDDEN>:
New bug report received and forwarded. Copy sent to bug-coreutils@HIDDEN. Full text available.
Report forwarded to bug-coreutils@HIDDEN:
bug#67593; Package coreutils. Full text available.
Please note: This is a static page, with minimal formatting, updated once a day.
Click here to see this page with the latest information and nicer formatting.
Last modified: Sun, 3 Dec 2023 09:45:01 UTC

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997 nCipher Corporation Ltd, 1994-97 Ian Jackson.