If BROWSER isn't set, sensible-browser outputs: "usage: which [-as] program ..."

[Paulo Marcel Coelho Aragão]

If environment variable BROWSER isn't set, sensible-browser always shows this error message:

usage: which [-as] program ...

even though it goes on and opens the browser.

It's easy to reproduce:

$ unset BROWSER
$ sensible-browser http://example.com

The bug is right at the beginning:

# Prevent recursive loops, where these values are set to this script
p="$(which sensible-browser)"
[ "$(which $BROWSER || true)" = "$p" ] && BROWSER=

It could be fixed with:

[ -n "$BROWSER" -a "$(which "$BROWSER")" = "$p" ] && BROWSER=

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: sensible-utils 0.0.12
ProcVersionSignature: Ubuntu 4.15.0-29.31-generic 4.15.18
Uname: Linux 4.15.0-29-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
CurrentDesktop: XFCE
Date: Wed Jul 18 20:21:36 2018
Dependencies:

InstallationDate: Installed on 2018-04-28 (81 days ago)
InstallationMedia: Xubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
PackageArchitecture: all
SourcePackage: sensible-utils
UpgradeStatus: No upgrade log present (probably fresh install)