I have one use case where this will be useful.>> The same way it is possible to delete duplicates in minibuffer history,
>> I think it is also very useful to have the possibility to ignore
>> entries starting with space(s). The new variable `history-ignore-space'
>> would take care of this, being `nil' its defaut value.
>
> Could you explain some use cases?
In http://thread.gmane.org/gmane.emacs.devel/91359/focus=92106
I suggested a piece of code for .emacs that removes potentially
dangerous commands from the minibuffer history.
With a new variable `history-ignore-space'=t this will be unnecessary
since it's possible to not put dangerous commands to the minibuffer history
with just prepending a command with a space like e.g. " rm -rf ."