mq: catch attempt to qpush to an earlier patch (issue2587) We can't assume that all pushable patches early in the series have already been applied. If a hg qselect is done while you already have patches applied, some patches with guards may now be pushable, even though they come earlier in the series. So instead of checking only applied patches, explicitly check where we are in the series against the position of the patch we want to qpush to.