From 54cc9d01ad3f0a0a9d9b9fd4bd58ae699e38e5fa Mon Sep 17 00:00:00 2001
From: Tim Pope <code@tpope.net>
Date: Mon, 12 Apr 2021 13:29:49 -0400
Subject: [PATCH] Always set b:git_dir

This makes it possible to tell when detection hasn't happened yet, and
is potentially a stepping stone to doing it on the fly.
---
 autoload/fugitive.vim | 2 +-
 plugin/fugitive.vim   | 9 +++------
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/autoload/fugitive.vim b/autoload/fugitive.vim
index cb6047c..2afc417 100644
--- a/autoload/fugitive.vim
+++ b/autoload/fugitive.vim
@@ -2371,8 +2371,8 @@ function! s:TempReadPre(file) abort
     endif
     setlocal buftype=nowrite
     setlocal nomodifiable
+    let b:git_dir = dict.dir
     if len(dict.dir)
-      let b:git_dir = dict.dir
       call extend(b:, {'fugitive_type': 'temp'}, 'keep')
     endif
   endif
diff --git a/plugin/fugitive.vim b/plugin/fugitive.vim
index 58d6c22..0c3affe 100644
--- a/plugin/fugitive.vim
+++ b/plugin/fugitive.vim
@@ -137,7 +137,7 @@ function! FugitiveHead(...) abort
 endfunction
 
 function! FugitiveStatusline(...) abort
-  if !exists('b:git_dir')
+  if empty(get(b:, 'git_dir', ''))
     return ''
   endif
   return fugitive#Statusline()
@@ -277,12 +277,9 @@ function! FugitiveDetect(path) abort
     unlet b:git_dir
   endif
   if !exists('b:git_dir')
-    let dir = FugitiveExtractGitDir(a:path)
-    if dir !=# ''
-      let b:git_dir = dir
-    endif
+    let b:git_dir = FugitiveExtractGitDir(a:path)
   endif
-  if !exists('b:git_dir') || !exists('#User#Fugitive')
+  if empty(b:git_dir) || !exists('#User#Fugitive')
     return ''
   endif
   if v:version >= 704 || (v:version == 703 && has('patch442'))