bug#23425: master branch: `message' wrongly corrupts ' to curly quote.

[Paul Eggert]

On 06/08/2017 10:34 AM, Alan Mackenzie wrote:
> YUCK! So we'd have both message and memo doing basically the 
> samething, with different interfaces.

If it’s the API difference you object to, it’d be OK for the two 
functions to have the same signature. It’s no big deal.

> you've got two functions which are so close to each other, one single function 
> would be better.....

If having one single function would mean changing hundreds or thousands 
of callers, then there is an important sense in which one single 
function would not be better.

> NOBODY will write (message "30%-50% done")

Admittedly the example was contrived, but I thought it was cool how one 
can use % to delete parts of messages, something that is much worse than 
quote restyling. More commonly people compute a message string S 
somewhere else and then call (message S), and that does have real 
problems with %, particularly in situations where an adversary has some 
control over the contents of S.

> > It’s not intended to be “surreptitious” or “hidden” or anything like that, ....
> That may be the case, but it _seems_ very much like it.  If the intention had 
> actually been to be surreptitious, what more could have been done than was 
> actually done?

Lots. We discussed and rejected more-“surreptitious” options back before 
this stuff was installed. For example, we discussed changing ‘format’ to 
behave like ‘format-message’ does now.