[dev] [dvtm] dvtm seems to be only terminal not affected by GNU/Linux ecosystem bug I found

From: Askar Safin <safinaskar_AT_mail.ru>
Date: Tue, 18 Aug 2015 12:01:18 +0300

Hi. I found a bug which I call "GNU/Linux ecosystem bug", because there is no single software where this bug is located. Steps to reproduce:
1. Open a terminal. This can be X terminal emulator, such as konsole (sic!) or xterm. And this can be terminal multiplexer such as dvtm or tmux
2. Type the following command to the terminal:

for ((I = 1; I <= 100; ++I)) { echo $I; }; CURSES

CURSES should be replaced with some curses-like program, such as mc, less, dvtm, tmux. If you start some multiplexer in itself, you probably
need to force this operation. For example, in case of tmux, write "TMUX="" tmux" instead of plain "tmux". If you started tmux in itself, then Ctrl-b will
send commands to outer tmux and Ctrl-b Ctrl-b to inner tmux. Same for dvtm

3. Make the (outer) terminal smaller in vertical direction. If this is X terminal emulator, you can just make it smaller using mouse. If this is multiplexer,
then open new pane on the top or on the bottom
4. Exit from (inner) curses-like app

Now I see something like this:

82
83
[exited]
34 2015-07-09 19:38:32 ~$ _

But I expected to see:

99
100
[exited]
34 2015-07-09 19:38:32 ~$ _

The bug is reproducible with terminals: konsole, xterm, tmux, but not dvtm. And with curses-like apps: mc, tmux, dvtm, but not less. Versions used:
debian jessie 8, kde 4, tmux 1.9, konsole 2.14.2, bash 4.3, less 458, mc 4.8.13, xterm 312, dvtm 0.12.

The bug was sent to tmux ( https://github.com/tmux/tmux/issues/40 , https://github.com/tmux/tmux/issues/70 ) and konsole
( https://bugs.kde.org/show_bug.cgi?id=350951 ).

So, I have questions: where is this bug located? In terminals or in curses-like apps? Or in libcurses itself? Or in the kernel or somewhere
else? :) And why there is no this bug in dvtm, but it is present in other terminals?
==
Askar Safin
http://vk.com/safinaskar
Received on Tue Aug 18 2015 - 11:01:18 CEST

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