From 2fc1a0017c82d54dd4fac2a7d88db463478a158b Mon Sep 17 00:00:00 2001
From: Tim Pope <code@tpope.net>
Date: Tue, 17 Aug 2021 14:39:57 -0400
Subject: [PATCH] Accept buffer numbers and dictionaries in FugitiveDetect()

This makes it easier to use FugitiveDetect() to initialize a temp file
that sits outside of the repository.
---
 plugin/fugitive.vim | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/plugin/fugitive.vim b/plugin/fugitive.vim
index 59d15d2..63c6c88 100644
--- a/plugin/fugitive.vim
+++ b/plugin/fugitive.vim
@@ -299,7 +299,13 @@ function! s:CeilingDirectories() abort
 endfunction
 
 function! FugitiveExtractGitDir(path) abort
-  let path = s:Slash(a:path)
+  if type(a:path) ==# type({})
+    return get(a:path, 'git_dir', '')
+  elseif type(a:path) == type(0)
+    let path = s:Slash(a:path >= 0 ? bufname(a:path) : bufname(''))
+  else
+    let path = s:Slash(a:path)
+  endif
   if path =~# '^fugitive:'
     return matchstr(path, '\C^fugitive:\%(//\)\=\zs.\{-\}\ze\%(//\|::\|$\)')
   elseif empty(path)
@@ -355,7 +361,7 @@ function! FugitiveExtractGitDir(path) abort
   return ''
 endfunction
 
-function! FugitiveDetect(path) abort
+function! FugitiveDetect(...) abort
   if v:version < 704
     return ''
   endif
@@ -363,7 +369,7 @@ function! FugitiveDetect(path) abort
     unlet b:git_dir
   endif
   if !exists('b:git_dir')
-    let b:git_dir = FugitiveExtractGitDir(a:path)
+    let b:git_dir = FugitiveExtractGitDir(a:0 ? a:1 : bufnr(''))
   endif
   if empty(b:git_dir) || !exists('#User#Fugitive')
     return ''