Comment # 3 on bug 901115 from Ingo Buse

Created attachment 614918 [details]
Yast2 Log

i can confirm this behaviour:

in /etc/sysconfig/mail
have: MAIL_CREATE_CONFIG="yes"

nano /etc/postfix/main.cf
- change some config, i did:
 - inet_protocols = ipv4 ( was "all" )
 - inet_interfaces = all ( was "local" )

cp /etc/postfix/main.cf /etc/postfix/main.cf_tmp
yast lan (or yast network, than choose lan)
- add another ip-address
- save configuration

diff /etc/postfix/main.cf /etc/postfix/main.cf_tmp
< inet_interfaces = localhost
< inet_protocols = all
---
> inet_interfaces = all
> inet_protocols = ipv4

also the master.cf was modified as well, adding the # before tlsmgr again.
there were no backup-files of main.cf or master.cf created.
i dont recall having had this problem in 11.x, and i usually edit the main.cf
and master.cf directly.