with LANG=C, fragments of lines get superimposed/intertwined when paging up and down

[Bas van den Dikkenberg]

By scrolling down a file the layout is screwd up.

example i scrole in zone file of dns server i get this :

dhcp IN NS ns1
dhcp IN NS ns2
dhcp IN NS every cns3
dhcp IN NSfresh ( ns4urs)

vpn IN NSxpire ns1
vpn IN NSnimum ( ns2urs)
vpn IN NS ns3
vpn me servers IN NS ns4

But i realy looks like this :

dhcp IN NS ns1
dhcp IN NS ns2
dhcp IN NS ns3
dhcp IN NS ns4

vpn IN NS ns1
vpn IN NS ns2
vpn IN NS ns3
vpn IN NS ns4

When i edit and save everyting is stored correctly but on display it's wrong.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: nano 2.9.3-2
ProcVersionSignature: Ubuntu 4.15.0-29.31-generic 4.15.18
Uname: Linux 4.15.0-29-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.2
Architecture: amd64
Date: Sun Aug 5 15:54:27 2018
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=C
 SHELL=/bin/bash
SourcePackage: nano
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Bastiaan (bastiaan82-deactivatedaccount)]

I can confirm the bug

[Bas van den Dikkenberg (bas-dikkenberg)]

i made a video showing the problem i think thats beter than my description

[Bas van den Dikkenberg (bas-dikkenberg)]

the link :-D
https://youtu.be/MaPlL-L43w0

[Benno Schulenberg (bennoschulenberg)]

On which terminal emulator are you seeing this effect? What is the output of the 'locale' command? Can you attach the DNS zone file you were looking at? Can you search your system for a file that contains the word fragments "every", "fresh", "urs", "xpire" and "nimum"? Because it seems the zone file gets interleaved with another.

[Bas van den Dikkenberg (bas-dikkenberg)]

The zone file is just example it also happen when editing a big random file

The words you see are in the same file

[Benno Schulenberg (bennoschulenberg)]

Please answer also the other questions: which terminal, and the full output of 'locale'. Further, did you fiddle with your system? Have you symlinked some libraries? Also, are you able to build nano from source? If so, please try building the latest 2.9.8, and see how it fares.

[Bas van den Dikkenberg (bas-dikkenberg)]

arcording ubuntu-bug TERM=xterm
but it doesn't matter.
I didn't fiddle

THe problem is there even via console tty1 or ssh session

[Benno Schulenberg (bennoschulenberg)]

Dang. How hard is it to answer *all* questions? Provide the full output of 'locale' on the affected machine.

[Benno Schulenberg (bennoschulenberg)]

By the way: please delete your sockpuppet bastiaan82.

[Bas van den Dikkenberg (bas-dikkenberg)]

Sorry missing that question, in my defense my mother got commited to the hospital and wasn't clear minded

I am willing to provide the file to you in private mail

root@domein:~# locale
LANG=C
LANGUAGE=
LC_CTYPE="C"
LC_NUMERIC="C"
LC_TIME="C"
LC_COLLATE="C"
LC_MONETARY="C"
LC_MESSAGES="C"
LC_PAPER="C"
LC_NAME="C"
LC_ADDRESS="C"
LC_TELEPHONE="C"
LC_MEASUREMENT="C"
LC_IDENTIFICATION="C"
LC_ALL=
root@domein:~#

[Bas van den Dikkenberg (bas-dikkenberg)]

don't know what a sockpuppet is bastiaan82 is not my account !

[Bastiaan (bastiaan82-deactivatedaccount)]

Estaba bromeando Bas

[Bas van den Dikkenberg (bas-dikkenberg)]

I just noticed that it happens with pgup en pgdown keys not wit cursor keys.
To morrow i will try to compile the recent nano

[Benno Schulenberg (bennoschulenberg)]

Thanks for the files you sent via private email. However, I am unable to reproduce the effect that you see.

Also, this report has *not* been confirmed. You are the only person who is seeing this effect -- or have only one machine that displays this behavior. I am suspecting an anomaly in your setup, which (when you move to another page) makes ncurses think that there are already spaces on the rows that it should draw and therefore does not bother to draw them.

What is the output of 'stty size'? Do you use 'stty' to change the number of columns or rows from what they actually are?

Further, do you see the effect also when you use 'nano --ignore' instead of plain 'nano'? And what when you run 'LANGUAGE=en nano --ignore'?

The machine that you see the effect on, is it a server? Did you see this effect since 18.04 was installed, or did it develop later? How come that the locale of that machine is set to all "C"? Because as far as I know, most distros default to a Unicode locale nowadays.

[Bas van den Dikkenberg (bas-dikkenberg)]

It are all new installs ubuntu 18.04 server,
The bug was confirmd by 3 personens 1 acount was a fake (not by me!)

How can i see the ssty size ?

Nano --ignore same result
LANGUAGE=en nano --ignore /etc/nsd/zones/master/exampl.com same result

But the locale is the problem if LANG=C is set this problem is there.
I fixed this now on my system it was used in the past to fix display isue in mc.

So is it a bug when je set lang to c with.
You can reproduce when you do a export LANG=C

[Benno Schulenberg (bennoschulenberg)]

The bug *seemingly* affects three people: the reporter (you), one person who was clearly a fake, and one other person "confirmed" it by clicking that he/she is affected too. But an anonymous person whom I can't ask questions doesn't count as confirmation for me. And most likely that anonymous person is a sockpuppet too, because confirming a report so soon after it was filed...

As I said: run 'stty size' on your terminal, and paste the output.

When setting LANG=C, I still cannot reproduce the effect that you see.

What did you change LANG into to "fix" the problem?

So... in fact there is no problem? It was just an anomaly in your setup, as I suspected?

You saw the effect on new installs of Ubuntu 18.04 server. Can you make a fresh install (on a random, free partition) and take note of the choices that you make? So that I stand a chance of reproducing your environment.

[Benno Schulenberg (bennoschulenberg)]

Hmmm... When the line containing "Minimum" and the second "vpn" line should 'overlap' when doing a single PageDown, then your terminal must have 61 rows (when using --ignorercfiles). But... when I alternately do a PageDown and a PageUp, and look how exactly those two lines would interweave, then I can never see "vpn IN NSnimum ( ns2urs)", as you have posted, no matter what tabsize I use. With --tabsize=4, it would display "NSinimumns2__4_hours)" (where an underscore stands for a space), and with --tabsize=5 it would display "NSimum_(__ns2hours)" -- *if* tabs wouldn't be cleared properly.

So... how you can ever see "vpn IN NSnimum ( ns2urs)" without the "nimum" jumping left or right is a mystery to me. Can you give me an account on one of your servers, complete with the "faulty" environment that triggers the effect, so that I can see it for myself? A ssh key is attached.

[Bas van den Dikkenberg (bas-dikkenberg)]

Benno, can you supply me with an ip adres for the FW by sending it by private mail to me?

[Benno Schulenberg (bennoschulenberg)]

I've given you my IP address, but am unable to ssh into your server.

[Launchpad Janitor (janitor)]

[Expired for nano (Ubuntu) because there has been no activity for 60 days.]