Disable backing out merges?

[Matt Mackall]

On Thu, 2011-10-06 at 22:45 +0200, Arne Babenhauserheide wrote:
> Am Donnerstag, 6. Oktober 2011, 14:45:22 schrieb Matt Mackall:
> > Seems a bunch of people are trying to use backout to deal with broken
> > merges. That doesn't work:
> > 
> > - it's not well-defined what the result should be
> > - we can't actually erase the problematic DAG edge
> > 
> > So it seems like we should just refuse to do it until we get a lot
> > smarter here.
> 
> What about people who want to backout a set of changes which includes merges? 

They will get a broken result because backout is known not to work with
merges and we will thus have saved them pain.

> The only way to get rid of them after subsequent pushed commits are clean 
> backouts.

..except we know this doesn't actually work for merges and causes lots
of pain.

> Why not just *suggest* using revert instead when backout is used on a merge? 

Why is revert helpful? (See my response to Angel, please.)

> Or fix the backout logic?

I have no idea how to do that, and I actually suspect that a
satisfactory answer doesn't exist. If you know better, I'm ready to be
impressed.

-- 
Mathematics is the supreme nostalgia of our time.