drawing error with nvim

[atondwal]

Last line seems to draw incorrectly and wrap when using nvim (this example has me repeatedly typing o<Esc> in an empty file). Doesn't seem to happen with any other terminal emulator. Happens with empty init.vim and .mlterm configurations.

mlterm version 3.9.1 post/2021-04-09
Features: otl ssh implugin imagelib(builtin) utmp

NVIM v0.4.4
Build type: Release
LuaJIT 2.0.5
Compilation: /usr/bin/cc -D_FORTIFY_SOURCE=2 -march=x86-64 -mtune=generic -O2 -pipe -fno-plt -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1 -O2 -DNDEBUG -DMIN_LOG_LEVEL=3 -Wall -Wextra -pedantic -Wno-unused-parameter -Wstrict-prototypes -std=gnu99 -Wshadow -Wconversion -Wmissing-prototypes -Wimplicit-fallthrough -Wvla -fstack-protector-strong -fno-common -fdiagnostics-color=always -DINCLUDE_GENERATED_DECLARATIONS -D_GNU_SOURCE -DNVIM_MSGPACK_HAS_FLOAT32 -DNVIM_UNIBI_HAS_VAR_FROM -I/build/neovim/src/build/config -I/build/neovim/src/neovim-0.4.4/src -I/usr/include -I/build/neovim/src/build/src/nvim/auto -I/build/neovim/src/build/include
Compiled by builduser

Features: +acl +iconv +tui

[atondwal]

bisect implicates 34a54dae514f20ce2f1d7b847092fe0ffbdcfeee

[atondwal]

Ah, this is a matter of control characters! Since xterm accepts any of the U+0000 block control characters 0x00-0x1F for escape sequences, when our TERM=xterm, nvim will use them. This can solved for me by either setting TERM=kterm (or urxvt, st, etc...) or by editing

mlterm/vtemu/vt_parser.c

Line 4347 in 93a26d3

if ((bel_terminate && **str == CTL_BEL) || (use_c1 && **str == 0x9c)) {

to include the additional condition **str < 0x20 ||. Setting TERM solves the problem for me, so feel free to close, but if you want to maintain compatibility with xterm's termcap/info, might be worth fixing this.

[arakiken]

Thanks very much.

I'd like to understand the cause of this problem, but I couldn't reproduce it in my environment
(nvim 0.4.4, mlterm-3.9.1 on arch linux).
I think that it doesn't fix incompatiblity with xterm completely to add '**str < 0x20' to get_pt_in_esc_seq(),
I'm wondering how to fix it with another approach.

Would you start mlterm with --logseq option and send me ~/.mlterm/*.log ?
It will help me reproduce the problem.
If possible, I'd like to see the result of 'infocmp xterm' command on your system.

Regards,

[atondwal]

Thanks for the response! I'm also using nvim 0.4.4 on arch linux (seeing this with both mlterm-3.9.1 as well as master on a fresh arch install installed from the AUR
pts_11-20210420084942.log
)
xterm.infocmp.txt

[arakiken]

Thanks to your help, I found that mlterm-3.9.1 or before failed to parse OSC sequence which doesn't contain semicolon.
I fixed it, so I'd like you to test it.

48e7865#diff-c9af0817cb9fcedacbeb3ec34e3d026ce4da2ce96eda2bf96b76043ae8de0e6b

[atondwal]

Works great now!