podman: Wrong network namespace when exec in container created with --net=host

Is this a BUG REPORT or FEATURE REQUEST? (leave only one on its own line)

/kind bug

Description When a container is created with podman run --net=host all instances of podman exec to that container do not attach to the containers network namespace but use whatever network namespace they are executed in.

Steps to reproduce the issue:

ip netns add foo
ip netns exec foo podman run --net=host -d <image>
podman exec <cid> ip link

Describe the results you received: I receive a list of the network devices in my current network namespace.

Describe the results you expected: I expect to see the network devices currently present in the containers network namespace.

Additional information you deem important (e.g. issue happens only occasionally): I actually use --net=host to manually create a network namespace as root and then I use ip netns exec su --login -c "podman run --net=host ..." <user> to drop privileges and run a rootless container inside that namespace.

This allows me to put whatever I like into that namespace prior to running any container app. This is especially useful to put a macvlan or veth interface into a rootless container.

Output of podman version:

% podman version
Version:            1.6.2
RemoteAPI Version:  1
Go Version:         go1.13.3
OS/Arch:            linux/amd64

Output of podman info --debug:

probably not necessary

Package info (e.g. output of rpm -q podman or apt list podman):

% xbps-query podman
architecture: x86_64
build-date: 2019-10-28 09:08 UTC
filename-sha256: 9f02213136c2e47678d2a7df463ff39b38ef0bde9e2f423e06f8d8a25ad31f0b
filename-size: 17MB
homepage: https://podman.io/
install-date: 2019-11-02 14:30 UTC
installed_size: 52MB
license: Apache-2.0
maintainer: Cameron Nemo <camerontnorman@gmail.com>
metafile-sha256: 217e71f163e554521506eee062869443aa3467d1b3a4d1a3ded0f738b0ddbc4b
pkgver: podman-1.6.2_1
repository: https://alpha.de.repo.voidlinux.org/current
shlib-requires:
	libpthread.so.0
	libgpgme.so.11
	libassuan.so.0
	libgpg-error.so.0
	libseccomp.so.2
	librt.so.1
	libdevmapper.so.1.02
	libc.so.6
short_desc: Simple management tool for containers and images
source-revisions: podman:1c4242350be
state: installed

Additional environment details (AWS, VirtualBox, physical, etc.): Void Linux, physical machine.