Switching tmux panes with C-h broken with tmux master branch

[aborzunov]

I compiled from sources to enable sixel support on tmux master branch (commit ae8f2208c98e3c2d6e3fe4cad2281dce8fd11f31) and found that every navigation shortcut works except C-h.
Switching from vim to vim, of from vim to tmux pane with C-h also works.

I don't know if it is a real issue, because tmux 3.6 is not released yet, so feel free to close it if it is not relevant.

There is binding for it:

❯ tmux list-keys -T root | grep 'C-h'
bind-key -T root MouseDown3Pane         if-shell -F -t = "#{||:#{mouse_any_flag},#{&&:#{pane_in_mode},#{?#{m/r:(copy|view)-mode,#{pane_mode}},0,1}}}" { select-pane -t = ; send-keys -M } { display-menu -T "#[align=centre]#{pane_index} (#{pane_id})" -t = -x M -y M "#{?#{m/r:(copy|view)-mode,#{pane_mode}},Go To Top,}" < { send-keys -X history-top } "#{?#{m/r:(copy|view)-mode,#{pane_mode}},Go To Bottom,}" > { send-keys -X history-bottom } '' "#{?mouse_word,Search For #[underscore]#{=/9/...:mouse_word},}" C-r { if-shell -F "#{?#{m/r:(copy|view)-mode,#{pane_mode}},0,1}" "copy-mode -t=" ; send-keys -X -t = search-backward "#{q:mouse_word}" } "#{?mouse_word,Type #[underscore]#{=/9/...:mouse_word},}" C-y { copy-mode -q ; send-keys -l "#{q:mouse_word}" } "#{?mouse_word,Copy #[underscore]#{=/9/...:mouse_word},}" c { copy-mode -q ; set-buffer "#{q:mouse_word}" } "#{?mouse_line,Copy Line,}" l { copy-mode -q ; set-buffer "#{q:mouse_line}" } '' "#{?mouse_hyperlink,Type #[underscore]#{=/9/...:mouse_hyperlink},}" C-h { copy-mode -q ; send-keys -l "#{q:mouse_hyperlink}" } "#{?mouse_hyperlink,Copy #[underscore]#{=/9/...:mouse_hyperlink},}" h { copy-mode -q ; set-buffer "#{q:mouse_hyperlink}" } '' "Horizontal Split" h { split-window -h } "Vertical Split" v { split-window -v } '' "#{?#{>:#{window_panes},1},,-}Swap Up" u { swap-pane -U } "#{?#{>:#{window_panes},1},,-}Swap Down" d { swap-pane -D } "#{?pane_marked_set,,-}Swap Marked" s { swap-pane } '' Kill X { kill-pane } Respawn R { respawn-pane -k } "#{?pane_marked,Unmark,Mark}" m { select-pane -m } "#{?#{>:#{window_panes},1},,-}#{?window_zoomed_flag,Unzoom,Zoom}" z { resize-pane -Z } }
bind-key -T root M-MouseDown3Pane       display-menu -T "#[align=centre]#{pane_index} (#{pane_id})" -t = -x M -y M "#{?#{m/r:(copy|view)-mode,#{pane_mode}},Go To Top,}" < { send-keys -X history-top } "#{?#{m/r:(copy|view)-mode,#{pane_mode}},Go To Bottom,}" > { send-keys -X history-bottom } '' "#{?mouse_word,Search For #[underscore]#{=/9/...:mouse_word},}" C-r { if-shell -F "#{?#{m/r:(copy|view)-mode,#{pane_mode}},0,1}" "copy-mode -t=" ; send-keys -X -t = search-backward "#{q:mouse_word}" } "#{?mouse_word,Type #[underscore]#{=/9/...:mouse_word},}" C-y { copy-mode -q ; send-keys -l "#{q:mouse_word}" } "#{?mouse_word,Copy #[underscore]#{=/9/...:mouse_word},}" c { copy-mode -q ; set-buffer "#{q:mouse_word}" } "#{?mouse_line,Copy Line,}" l { copy-mode -q ; set-buffer "#{q:mouse_line}" } '' "#{?mouse_hyperlink,Type #[underscore]#{=/9/...:mouse_hyperlink},}" C-h { copy-mode -q ; send-keys -l "#{q:mouse_hyperlink}" } "#{?mouse_hyperlink,Copy #[underscore]#{=/9/...:mouse_hyperlink},}" h { copy-mode -q ; set-buffer "#{q:mouse_hyperlink}" } '' "Horizontal Split" h { split-window -h } "Vertical Split" v { split-window -v } '' "#{?#{>:#{window_panes},1},,-}Swap Up" u { swap-pane -U } "#{?#{>:#{window_panes},1},,-}Swap Down" d { swap-pane -D } "#{?pane_marked_set,,-}Swap Marked" s { swap-pane } '' Kill X { kill-pane } Respawn R { respawn-pane -k } "#{?pane_marked,Unmark,Mark}" m { select-pane -m } "#{?#{>:#{window_panes},1},,-}#{?window_zoomed_flag,Unzoom,Zoom}" z { resize-pane -Z }
bind-key -T root C-h                    if-shell "ps -o state= -o comm= -t '#{pane_tty}'       | grep -iqE '^[^TXZ ]+ +(\\S+\\/)?g?(view|l?n?vim?x?|fzf)(diff)?$'" "send-keys 'C-h'" "select-pane -L"

[cw0]

I'm not so sure the problem is limited to this plugin, I'm struggling to do it in vanilla tmux

[BriHan-Tech]

I believe the problem is due to the is-vim check. I have opened an issue with a solution.

#418 (comment)

Here is my repo w/ details:
https://github.com/BriHan-Tech/is-vim

[xuwei152]

What terminal are you using? I have had the same issues as you in the kitty terminal. I resolved the problem by adding

map ctrl+h send_text all \x1b[104;5u

to the kitty.conf

[renxzen]

map ctrl+h send_text all \x1b[104;5u

this worked for me in alacritty and ghostty too, thanks @xuwei152

alacritty:

[keyboard]
bindings = [
	{ key = "H", mods = "Control", chars = "\u001B[104;5u" },
]

ghostty:

keybind = ctrl+h=esc:[104;5u