Re: Emacs 27.1 released

[Eli Zaretskii]

> From: Mattias Engdegård <mattiase@acm.org>
> Date: Fri, 14 Aug 2020 14:51:31 +0200
> Cc: emacs-devel@gnu.org
> 
> 14 aug. 2020 kl. 08.02 skrev Eli Zaretskii <eliz@gnu.org>:
> 
> > We are assessing this from two very different points of view: you are
> > thinking about fixing the bug, and I'm thinking about the dangers of
> > some unintended consequences of the fix destabilizing Emacs 27.2's
> > version of Calc.  By their very nature, unintended consequences are
> > unknown to you and to me, so asking for any specific details is not
> > useful.
> 
> Sorry about the misunderstanding -- no malice intended. Version history 
> indicates that you were the one bringing Calc into the Emacs tree and did 
> quite some work on it at the time, so it would be daft to assume that you 
> didn't have good knowledge of the code. In other words, there may very well 
> be something you know about it that I could learn.

I actually didn't consider the code at all in this case, I tried to
approach the issue from the POV of risk management.

> However, I understand that you have made up your mind.

If you can look at the issue from my POV, and provide arguments
relevant to the risks of back-porting these changes, I'd appreciate
that very much, as that would allow me to have a second opinion.  What
bothers me is the risk of having the fix uncover as yet unknown
problems in the callers of the function that was fixed.  Do you have
any thoughts about that?  For example, if the callers are already
broken when the fixed function misbehaved (are they?), that would be a
strong argument to cherry-pick the changes, because they cannot
possibly break what is already broken.

IOW, I'm trying to weight the advantages of fixing a problem against
the potential dangers and risks, especially the unknown ones.  Any
help in this decision-making will be appreciated.