Failed switch between panels when inside Termdebug window

[ingjieye]

So I have vim inside Tmux. Everything's works great.
Bug after VIM 8.1, there's a feature called Termdebug that I can run gdb inside VIM.
It'll open some panels inside VIM.
When I'm inside debug panel inside VIM. I can't switch between panels as usual.

[christoomey]

Hi @ingjieye. Can you test a few things?

• What is the output of :verbose nmap <C-k> when run in the gdb pane?
• Does running :TmuxNavigateUp directly work, or similarly fail?

[ingjieye]

• :verbose nmap <C-k>:

n  <C-K>       * :TmuxNavigateUp<CR>
        Last set from ~/.vim/plugged/vim-tmux-navigator/plugin/tmux_navigator.vim line 21

• Directly running :TmuxNavigateUp inside gdb pane works.

I notice that gdb pane inside Vim is just a gdb running inside vim embedded terminal.
So turns out that the problem is how to map shot-cuts inside vim-term.

I've paste this pr's change into my .vimrc. 63120c1. Then I can switch panes between Vim and Tmux.

Except that when I switch out of vim-term.

The vim-term pane goes into text mode that when I switch back I have to press a to get it working.

So I've changed a little bit into

if exists(':tnoremap')
 tnoremap <silent> <c-h> <c-w>:TmuxNavigateLeft<cr>
 tnoremap <silent> <c-j> <c-w>:TmuxNavigateDown<cr>
 tnoremap <silent> <c-k> <c-w>:TmuxNavigateUp<cr>
 tnoremap <silent> <c-l> <c-w>:TmuxNavigateRight<cr>
 tnoremap <silent> <c-\> <c-w>:TmuxNavigatePrevious<cr>
endif

Every thing works fine.
I also have FZF installed and when I navigate FZF result with Ctrl + k / Ctrl + j. It haven't conflict as discussed in
#172
#128