Hi,

Zeno Davatz wrote:
> 
> This is another thing I learned from Linus Torvalds: Think practical
> don't think theoretical.
> 
> Think of the Users that run Ruby and let them tell you if something
> breaks and then fix based on the practical Use-Case. I prefer to see
> that something happens instead being afraid that it may happen. Why?
> Because it may not happen or it may happen differently then you
> thought.
> 
> I prefer real-life proof.

I'm inclined to doubt Linus takes such a wait-and-see approach
with regard to potential kernel panics, or potential rootkit
exploit vectors.

I'd be looking to migrate my servers to a different OS if he did.

Similarly, I would be vastly concerned, disappointed, disheartened,
and frankly incredulous were the ruby-core developers to allow a
potential (not to mention demonstrated) source of instability such
as this Hash#merge! inconsistency to remain lurking in the Ruby
language unaddressed, once it had been discovered.

As someone wrote on a different mailing list just a couple days
ago:

    Humans look at probability and say "this happens less
    than once is a <BIG NUMBER>" and perceive this to mean
    "it never happens".  The point here is that things
    that a well loaded, always running process will do so
    much work that these things that almost never happen
    can actually occur regularly.

    It is the classic case of it you are statistically
    unlikely to ever win the lottery, even if you play at
    every opportunity.  And yet - there are lottery
    winners every couple of weeks.  People forget this
    counter intuitive situation and would write off a bug
    that will bite them on the basis that it is "extremely
    unlikely", when you're running your code often enough
    "practically impossible" can become a yearly,
    quarterly, monthly, weekly or daily problem.

            (Brian Barrett, SDL mailing list, 17-Jan-2011)

In short: You may never experience this Hash#Merge issue personally.
But one of your users will.


Finally, as someone quite rightly chastised my 17-year-old punk ass
twenty-two years ago:

  A Toast:
    Here's to all Empirical Programmers; may their work never
    inhabit my disks.


Cheers,

Bill