with-lock-ex segfaults if given only one argument.

[Natalie Amery]

Steps to reproduce:

$ with-lock-ex foo
Segmentation fault (core dumped)

Expected behaviour (from package version 5.0.2 in Debian):

$ with-lock-ex foo
usage: with-lock-ex -w|-q|-f <lockfile> <command> <args>...
       with-lock-ex -l <lockfile>
       with-lock <lockfile> <command> <args>...

I'll try and remember to investigate further what the cause of the misbehaviour is on Monday.

Thanks,

Natalie.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: chiark-utils-bin 6.1.2
ProcVersionSignature: Ubuntu 5.4.0-88.99-generic 5.4.140
Uname: Linux 5.4.0-88-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.20
Architecture: amd64
CasperMD5CheckResult: pass
Date: Fri Oct 15 16:57:24 2021
InstallationDate: Installed on 2021-03-02 (227 days ago)
InstallationMedia: Ubuntu-Server 20.04.2 LTS "Focal Fossa" - Release amd64 (20210201.2)
ProcEnviron:
 TERM=screen
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: chiark-utils
UpgradeStatus: No upgrade log present (probably fresh install)