Visual glitch because of timer

[thecatbus]

Randomly leaves behind these visual glitches where the h-j-k-l movement command is displayed at cursor location. I tried systematically removing plugins and commenting out parts of my vimrc, the problem was traced to the call timer_start line. Seems to be a general vim issue but would be nice if you know of a fix.

[nburns]

Woah weird. Thanks for doing some investigation.

What does vim --version show?

[thecatbus]

VIM - Vi IMproved 8.2 (2019 Dec 12, compiled Dec  6 2020 16:01:42)
macOS version
Included patches: 1-2100
Compiled by Homebrew
Huge version without GUI.  Features included (+) or not (-):
+acl               -farsi             +mouse_sgr         +tag_binary
+arabic            +file_in_path      -mouse_sysmouse    -tag_old_static
+autocmd           +find_in_path      +mouse_urxvt       -tag_any_white
+autochdir         +float             +mouse_xterm       -tcl
-autoservername    +folding           +multi_byte        +termguicolors
-balloon_eval      -footer            +multi_lang        +terminal
+balloon_eval_term +fork()            -mzscheme          +terminfo
-browse            +gettext           +netbeans_intg     +termresponse
++builtin_terms    -hangul_input      +num64             +textobjects
+byte_offset       +iconv             +packages          +textprop
+channel           +insert_expand     +path_extra        +timers
+cindent           +ipv6              +perl              +title
-clientserver      +job               +persistent_undo   -toolbar
+clipboard         +jumplist          +popupwin          +user_commands
+cmdline_compl     +keymap            +postscript        +vartabs
+cmdline_hist      +lambda            +printer           +vertsplit
+cmdline_info      +langmap           +profile           +virtualedit
+comments          +libcall           -python            +visual
+conceal           +linebreak         +python3           +visualextra
+cryptv            +lispindent        +quickfix          +viminfo
+cscope            +listcmds          +reltime           +vreplace
+cursorbind        +localmap          +rightleft         +wildignore
+cursorshape       +lua               +ruby              +wildmenu
+dialog_con        +menu              +scrollbind        +windows
+diff              +mksession         +signs             +writebackup
+digraphs          +modify_fname      +smartindent       -X11
-dnd               +mouse             -sound             -xfontset
-ebcdic            -mouseshape        +spell             -xim
+emacs_tags        +mouse_dec         +startuptime       -xpm
+eval              -mouse_gpm         +statusline        -xsmp
+ex_extra          -mouse_jsbterm     -sun_workshop      -xterm_clipboard
+extra_search      +mouse_netterm     +syntax            -xterm_save
   system vimrc file: "$VIM/vimrc"
     user vimrc file: "$HOME/.vimrc"
 2nd user vimrc file: "~/.vim/vimrc"
      user exrc file: "$HOME/.exrc"
       defaults file: "$VIMRUNTIME/defaults.vim"
  fall-back for $VIM: "/usr/local/share/vim"
Compilation: clang -c -I. -Iproto -DHAVE_CONFIG_H   -DMACOS_X -DMACOS_X_DARWIN  -g -O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1       
Linking: clang   -L. -fstack-protector-strong -L/usr/local/lib -L/usr/local/opt/libyaml/lib -L/usr/local/opt/[email protected]/lib -L/usr/local/opt/readline/lib  -L/usr/local/lib -o vim        -lm  -lncurses -liconv -lintl -framework AppKit  -L/usr/local/opt/lua/lib -llua5.4 -mmacosx-version-min=11.0 -fstack-protector-strong -L/usr/local/lib  -L/usr/local/Cellar/perl/5.32.0/lib/perl5/5.32.0/darwin-thread-multi-2level/CORE -lperl  -L/usr/local/opt/[email protected]/Frameworks/Python.framework/Versions/3.9/lib/python3.9/config-3.9-darwin -lpython3.9 -framework CoreFoundation  -lruby.2.7     

[nburns]

VIM - Vi IMproved 8.2 (2019 Dec 12, compiled Sep 21 2020 04:03:24)
macOS version
Included patches: 1-1719
Compiled by [email protected]
Huge version with MacVim GUI.  Features included (+) or not (-):
+acl               +file_in_path      -mouse_sysmouse    -tag_old_static
+arabic            +find_in_path      +mouse_urxvt       -tag_any_white
+autocmd           +float             +mouse_xterm       -tcl
+autochdir         +folding           +multi_byte        +termguicolors
-autoservername    -footer            +multi_lang        +terminal
+balloon_eval      +fork()            -mzscheme          +terminfo
+balloon_eval_term +fullscreen        +netbeans_intg     +termresponse
+browse            +gettext           +num64             +textobjects
++builtin_terms    -hangul_input      +odbeditor         +textprop
+byte_offset       +iconv             +packages          +timers
+channel           +insert_expand     +path_extra        +title
+cindent           +ipv6              +perl/dyn          +toolbar
+clientserver      +job               +persistent_undo   +transparency
+clipboard         +jumplist          +popupwin          +user_commands
+cmdline_compl     +keymap            +postscript        +vartabs
+cmdline_hist      +lambda            +printer           +vertsplit
+cmdline_info      +langmap           +profile           +virtualedit
+comments          +libcall           +python/dyn        +visual
+conceal           +linebreak         +python3/dyn       +visualextra
+cryptv            +lispindent        +quickfix          +viminfo
+cscope            +listcmds          +reltime           +vreplace
+cursorbind        +localmap          +rightleft         +wildignore
+cursorshape       +lua/dyn           +ruby/dyn          +wildmenu
+dialog_con_gui    +menu              +scrollbind        +windows
+diff              +mksession         +signs             +writebackup
+digraphs          +modify_fname      +smartindent       -X11
+dnd               +mouse             -sound             -xfontset
-ebcdic            +mouseshape        +spell             +xim
+emacs_tags        +mouse_dec         +startuptime       -xpm
+eval              -mouse_gpm         +statusline        -xsmp
+ex_extra          -mouse_jsbterm     -sun_workshop      -xterm_clipboard
+extra_search      +mouse_netterm     +syntax            -xterm_save
-farsi             +mouse_sgr         +tag_binary
   system vimrc file: "$VIM/vimrc"
     user vimrc file: "$HOME/.vimrc"
 2nd user vimrc file: "~/.vim/vimrc"
      user exrc file: "$HOME/.exrc"
  system gvimrc file: "$VIM/gvimrc"
    user gvimrc file: "$HOME/.gvimrc"
2nd user gvimrc file: "~/.vim/gvimrc"
       defaults file: "$VIMRUNTIME/defaults.vim"
    system menu file: "$VIMRUNTIME/menu.vim"
  fall-back for $VIM: "/Applications/MacVim.app/Contents/Resources/vim"
Compilation: clang -c -I. -Iproto -DHAVE_CONFIG_H -DFEAT_GUI_MACVIM -Wall -Wno-unknown-pragmas -pipe  -DMACOS_X -DMACOS_X_DARWIN  -g -O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1 -Wall -Wextra -Wshadow -Werror -Wno-error=missing-field-initializers -Wno-error=deprecated-declarations -Wno-error=unused-function
Linking: clang   -L. -fstack-protector-strong -L/usr/local/lib -L/usr/local/opt/libyaml/lib -L/usr/local/opt/[email protected]/lib -L/usr/local/opt/readline/lib -L. -fstack-protector-strong -L/usr/local/lib -L/usr/local/opt/libyaml/lib -L/usr/local/opt/[email protected]/lib -L/usr/local/opt/readline/lib  -L/usr/local/lib -o Vim -framework Cocoa -framework Carbon       -lm  -lncurses -liconv /usr/local/lib/libintl.a -framework AppKit   -fstack-protector  -L/System/Library/Perl/5.18/darwin-thread-multi-2level/CORE

[thecatbus]

Possibly the problem is me running vim on terminal? Haven't used a GUI so can't tell.

[nburns]

I've tested it in the terminal, but generally I use MacVim.app, so it's not like I'd notice a infrequent terminal bug. Is it common and repeatable, or just happens sometimes?

How did you remove the plugins (did you remove the files or just comment out lines from your vimrc)? What plugin manager do you use?

This is my first vim plugin, so I'm not totally sure where to look. My first hunch would be something about your config or other plugins.

[thecatbus]

It happens as soon as the timer is called. I tried loading a clean rc and deleting all plugin files (I use vim8 inbuilt package system and no manager), the glitch doesnt appear when there are no plugins. I tried loading a clean vimrc with only the gist of the mechanism (i.e. a function that sends the enquiry and sets theme) and the problem appeared as soon as I manually called the repeat timer.

It is frequent enough to be noticeable: a simple :redraw! (or switching the line when using cursorline) removes all glitches, but the system is noticeably clunkier nonetheless- letters are typed twice every now and then too.

Maybe running the process asynchronously could be a solution? I don't know enough about this to say for sure.