Comment # 10 on bug 927616 from Bernhard Wiedemann

I did not need this much, but I re-tested this on openSUSE Leap 15.0
and found that ifup wlan1 still left the interface in "state DOWN"

iwconfig shows ESSID:off/any

so still the somewhat broken state of 2015.

 # cat ifcfg-wlan1
STARTMODE='auto'
BOOTPROTO='static'
BROADCAST='192.168.7.255'    
IPADDR='192.168.7.3'
NAME='RTL8192CU 802.11n WLAN Adapter'
NETMASK='255.255.255.0'
NETWORK='192.168.7.0'
WIRELESS_AP=''
WIRELESS_AP_SCANMODE='1'
WIRELESS_AUTH_MODE='no-encryption' 
WIRELESS_BITRATE='auto'
WIRELESS_DEFAULT_KEY='0'
WIRELESS_ESSID='wlanbridge'
WIRELESS_KEY_LENGTH='128'
WIRELESS_MODE='Ad-hoc'
WIRELESS_POWER='no'

Also, wpa_supplicant is still started.