From 88242397b4d2fc03d20db189da84869ffbc31b64 Mon Sep 17 00:00:00 2001
From: Mark Woods <mwoods.online.ie@gmail.com>
Date: Thu, 20 Jan 2022 16:51:39 +0000
Subject: [PATCH] Only set ballooneval while in tagbar window (#805)

ballooneval is a global option, so setting it while initialising tagbar
permanently enables ballooneval functionality for the GUI, overriding
the vim default (disabled) or a user explicitly setting noballooneval.

To address this, only set ballooneval when entering the tagbar window,
and restore the original ballooneval setting when leaving the window.

This is not perfect, but there is precedent, Netrw behaves like this.
---
 autoload/tagbar.vim | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/autoload/tagbar.vim b/autoload/tagbar.vim
index 51865f0..4318122 100644
--- a/autoload/tagbar.vim
+++ b/autoload/tagbar.vim
@@ -563,6 +563,16 @@ function! s:CreateAutocommands() abort
             autocmd WinEnter   __Tagbar__.* call s:SetStatusLine()
             autocmd WinLeave   __Tagbar__.* call s:SetStatusLine()
 
+            if g:tagbar_show_balloon == 1 && has('balloon_eval')
+                autocmd WinEnter __Tagbar__.*
+                        \ let s:beval = &beval |
+                        \ set ballooneval
+                autocmd WinLeave __Tagbar__.*
+                        \ if exists("s:beval") |
+                        \   let &beval = s:beval |
+                        \ endif
+            endif
+
             if g:tagbar_autopreview
                 autocmd CursorMoved __Tagbar__.* nested call s:ShowInPreviewWin()
             endif
@@ -989,7 +999,6 @@ function! s:InitWindow(autoclose) abort
 
     if g:tagbar_show_balloon == 1 && has('balloon_eval')
         setlocal balloonexpr=TagbarBalloonExpr()
-        set ballooneval
     endif