Re: open-{gnutls,network}-stream backwards compatibility

[Eli Zaretskii]

> From: Robert Pluim <address@hidden>
> Date: Wed, 02 Jan 2019 17:49:13 +0100
> 
> 1.  As part of that fix, Iʼd like to change the signature of
>     open-gnutls-stream from
> 
>     (open-gnutls-stream name buffer host service &optional nowait)
> 
>     to
> 
>     (open-gnutls-stream name buffer host service &optional nowait parameters)
> 
>     Normally this would be fine, I think, except that the caller in
>     Emacs core derives the value of 'nowait' from the plist that would be
>     passed in via 'parameters' anyway, so Iʼm tempted to just change it
>     to:
> 
>     (open-gnutls-stream name buffer host service &optional parameters)
> 
>     then adjust the single in-core caller and have open-gnutls-stream
>     call plist-get.
> 
>     Does anyone see any issue with doing this?

How about changing the code so that PARAMETERS could also be a symbol,
in which case it would be interpreted in backward-compatible way?

>     Again Iʼm tempted to change open-network-stream such that not
>     specifying :client-certificate is the same as specifying t, so
>     that all Emacs core and external packages can take advantage of
>     the feature just by adjusting their .authinfo entries, similarly
>     to how password lookup automatically works today. However, this
>     would be a change in default behaviour, plus I know some people
>     are very sensitive to changes in this particular area, so I
>     thought Iʼd ask here before doing anything.

IMO, we should resist the temptation of making backward-incompatible
changes.  From bitter experience, even obscure internal functions are
sometimes used, and their users don't expect us to break the APIs.