Re: [PATCH] add receive.denyNonFastforwards config variable

> Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:
> 
> > If receive.denyNonFastforwards is set to true, git-receive-pack will deny
> > non fast-forwards, i.e. forced updates. Most notably, a push to a repository
> > which has that flag set to true will fail.
> >
> > As a first user, 'git-init-db --shared' sets this flag, since in a shared
> > setup, you are most unlikely to want forced pushes to succeed.
> 
> I am Ok with the general idea, but ...
> 
> > @@ -127,6 +129,16 @@ static int update(struct command *cmd)
> >  		return error("unpack should have generated %s, "
> >  			     "but I can't find it!", new_hex);
> >  	}
> > +	if (deny_non_fast_forwards) {
> > +		struct commit *old_commit, *new_commit;
> > +		old_commit = (struct commit *)parse_object(old_sha1);
> > +		new_commit = (struct commit *)parse_object(new_sha1);
> > +		struct commit_list *bases = get_merge_bases(old_commit,
> > +				new_commit, 1);
> > +		if (!bases || hashcmp(old_sha1, bases->item->object.sha1))
> > +			return error("denying non-fast forward;"
> > +					" you should pull first");
> > +	}
> >  	safe_create_leading_directories(lock_name);
> >  
> >  	newfd = open(lock_name, O_CREAT | O_EXCL | O_WRONLY, 0666);
> 
> I am wondering if there can be more than one base and the old_sha1
> is not returned as the first one.