From 4e6b7b6ce9beac6533790392ed869793802604cd Mon Sep 17 00:00:00 2001
From: Tim Pope <code@tpope.net>
Date: Sat, 21 Aug 2021 19:19:55 -0400
Subject: [PATCH] Don't accept 0 to refer to alternate buffer

This allows a sensible interpretation when using 0 as a stand-in for
"false".  You can use bufnr('#') if you need the old behavior.
---
 plugin/fugitive.vim | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/plugin/fugitive.vim b/plugin/fugitive.vim
index 4cd3ef1..2a2ee9f 100644
--- a/plugin/fugitive.vim
+++ b/plugin/fugitive.vim
@@ -18,7 +18,7 @@ let s:bad_git_dir = '/$\|^fugitive:'
 function! FugitiveGitDir(...) abort
   if v:version < 704
     return ''
-  elseif !a:0 || type(a:1) == type(0) && a:1 < 0
+  elseif !a:0 || type(a:1) == type(0) && a:1 < 0 || a:1 is# get(v:, 'true', -1)
     if exists('g:fugitive_event')
       return g:fugitive_event
     endif
@@ -30,7 +30,7 @@ function! FugitiveGitDir(...) abort
       return b:git_dir
     endif
     return dir =~# s:bad_git_dir ? '' : dir
-  elseif type(a:1) == type(0)
+  elseif type(a:1) == type(0) && a:1 isnot# 0
     if a:1 == bufnr('') && (!exists('b:git_dir') || b:git_dir =~# s:bad_git_dir) && empty(&buftype)
       let b:git_dir = FugitiveExtractGitDir(expand('%:p'))
     endif