Hi,
Grml's zshrc [http://grml.org/zsh/] uses 'setopt share_history' by default since ages.
This option is responsible for making the history of one Zsh session available to others "kind-of-immediately". So when sending 'echo foobar' in one terminal, then pressing e.g. <return> in another zsh session of the same user then cursor up will show 'echo foobar' on the command line.
While I personally like the feature and somewhat got used to it it's also one of the most discussed settings of grml-zshrc. It has the potential to do harm, especially if you aren't aware of that feature.
This is why I'd like to disable this setting by default (but provide it as commented feature so it's trivial to just enable it on request). Of course you will be able to just customize it via e.g. .zshrc.local, it's really just about the default behaviour.
Any objections against that switch? Happy to hear your {N,}ACKs. :)
regards, -mika-