Soliciting feedback for python port changes (libedit v. readline)

[Rainer Müller]

On 2016-04-22 19:06, Eric A. Borisch wrote:
> Ideally we would track down when this (python+libedit) broke; if someone
> has the time and motivation to do that, please raise your hand!

As noted in ticket #48807, it works fine with libedit @20140620-3.1_0,
but not with libedit @20150325-3.1_0.

After some debugging and diffing of the two libedit versions, I found
the change in the libedit source that broke this and that lead me to
this bug report:

https://gnats.netbsd.org/48957

I confirmed that commenting out that el_set() again will fix the issue
with python.

Basically this patch reverted a change that came from a patch from
Apple. The libedit provided by Apple also still seems to contain this
commented out code line [1].

The cpython readline module has lots of #ifdef __APPLE__ code [2].
I suppose somewhere in this module, cpython relies on the wrong behavior
of libedit as introduced by Apple – which was corrected by upstream.

Rainer

[1] https://opensource.apple.com/source/libedit/libedit-43/src/readline.c
[2] https://hg.python.org/cpython/file/tip/Modules/readline.c