Re: Behaviour change in 8.0 with empty input and no prompt

[Chet Ramey]

On 11/16/22 12:19 AM, Kevin Pulo wrote:
> Apologies if this has already been discussed; I tried searching the
> mailing list, but came up empty.
>
> I noticed that in readline 8.0 and later, if there is no prompt and I
> press Enter with an empty input line, readline does not output a
> newline.  Earlier versions of readline did output a newline in this
> situation.

Yes, since the cursor is at position 0 on an empty line, the readline
redisplay suppresses the newline. This is the desired behavior when,
for instance, you have multiple input lines and the cursor has just
wrapped to the final line. Readline doesn't make a distinction between
cases here, so your example also has the final newline suppressed.


> Was this change deliberate?  If so, is there a way to get the old
> behaviour back (and if not, could an option be added)?  If the change
> was not intentional, can it be considered a bug and the behaviour
> reverted?

It's not a bug. It's a fix for this redisplay issue:

https://lists.gnu.org/archive/html/bug-readline/2018-09/msg00004.html

I could see making an exception if there is only one input line. Let me
look at that.


--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/