`command -pv` does not restrict search to same directories as `command -p`

[Jarno Suni]

This works differently than bash in this case.
Say you have /opt in PATH and x in /opt.
 dash -c "command -pv x"
prints "/opt/x" and exits with 0 whereas
 bash -c "command -pv x"
prints nothing and exits with 1.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: dash 0.5.7-4ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-76.120-lowlatency 3.13.11-ckt30
Uname: Linux 3.13.0-76-lowlatency x86_64
ApportVersion: 2.14.1-0ubuntu3.19
Architecture: amd64
CurrentDesktop: XFCE
Date: Sat Jan 30 17:28:05 2016
EcryptfsInUse: Yes
InstallationDate: Installed on 2014-09-21 (496 days ago)
InstallationMedia: Ubuntu-Studio 14.04.1 LTS "Trusty Tahr" - Release amd64 (20140722.1)
SourcePackage: dash
UpgradeStatus: No upgrade log present (probably fresh install)