From 92a23103e3905f84b040c65ea589c9c7b47fdc68 Mon Sep 17 00:00:00 2001
From: "Kenneth Benzie (Benie)" <benie@infektor.net>
Date: Wed, 27 Jan 2021 19:23:13 +0000
Subject: [PATCH] Fix vim-tmux-focus-events errors in command-line

When changing focus away and back to vim while in the middle of editing
the command-line, vim-tmux-focus-events emits errors from the function
called by the `:cnoremap` mappings. This patch replaces these mappings
with a call to `do#sink()` which does nothing. Simply removing the
mappings will result in `<F24><F25>` being inserted on the command-line
since tmux will send this text when `tmux set-option -g focus-events
on`, this is why `do#sink()` is needed.
---
 after/plugin/mappings.vim | 8 ++++++++
 autoload/do.vim           | 4 ++++
 2 files changed, 12 insertions(+)
 create mode 100644 after/plugin/mappings.vim

diff --git a/after/plugin/mappings.vim b/after/plugin/mappings.vim
new file mode 100644
index 0000000..01a0398
--- /dev/null
+++ b/after/plugin/mappings.vim
@@ -0,0 +1,8 @@
+if get(g:, 'loaded_tmux_focus_events', 0)
+  " Override vim-tmux-focue-events command-line mappings when tmux send <F24>
+  " FocusLost and <F25> FocusLost instead of to call do#sink() which does
+  " nothing. This is required due to errors emitted from the
+  " vim-tmux-focus-events plugin when chaning focus.
+  cnoremap <silent> <F24> <C-\>edo#sink()<CR>
+  cnoremap <silent> <F25> <C-\>edo#sink()<CR>
+endif
diff --git a/autoload/do.vim b/autoload/do.vim
index 68ba12e..aca11c8 100644
--- a/autoload/do.vim
+++ b/autoload/do.vim
@@ -96,3 +96,7 @@ function! do#signify() abort
   " Enable update on text change e.g. undo/redo
   autocmd signify TextChanged <buffer> call sy#start()
 endfunction
+
+" A sink for mappings to do nothing
+function! do#sink() abort
+endfunction