Separate detection from initialization

plugin/fugitive.vim

@@ -62,7 +62,7 @@ endfunction
 
 function! s:shellslash(path) abort
   if s:winshell()
-    return s:gsub(a:path,'\\','/')
+    return tr(a:path, '\', '/')
   else
     return a:path
   endif
@@ -151,19 +151,15 @@ endfunction
 
 let s:abstract_prototype = {}
 
-" Section: Initialization
+" Section: Detection
 
 function! FugitiveIsGitDir(path) abort
-  let path = s:sub(a:path, '[\/]$', '') . '/'
+  let path = substitute(a:path, '[\/]$', '', '') . '/'
   return getfsize(path.'HEAD') > 10 && (
         \ isdirectory(path.'objects') && isdirectory(path.'refs') ||
         \ getftype(path.'commondir') ==# 'file')
 endfunction
 
-function! fugitive#is_git_dir(path) abort
-  return FugitiveIsGitDir(a:path)
-endfunction
-
 function! FugitiveExtractGitDir(path) abort
   if s:shellslash(a:path) =~# '^fugitive://.*//'
     return matchstr(s:shellslash(a:path), '\C^fugitive://\zs.\{-\}\ze//')
@@ -195,7 +191,7 @@ function! FugitiveExtractGitDir(path) abort
         return s:dir_for_worktree[root]
       endif
     endif
-    let dir = s:sub(root, '[\/]$', '') . '/.git'
+    let dir = substitute(root, '[\/]$', '', '') . '/.git'
     let type = getftype(dir)
     if type ==# 'dir' && FugitiveIsGitDir(dir)
       return dir
@@ -217,10 +213,6 @@ function! FugitiveExtractGitDir(path) abort
   return ''
 endfunction
 
-function! fugitive#extract_git_dir(path) abort
-  return FugitiveExtractGitDir(a:path)
-endfunction
-
 function! FugitiveDetect(path) abort
   if exists('b:git_dir') && (b:git_dir ==# '' || b:git_dir =~# '/$')
     unlet b:git_dir
@@ -235,6 +227,23 @@ function! FugitiveDetect(path) abort
     endif
   endif
   if exists('b:git_dir')
+    return fugitive#Init()
+  endif
+endfunction
+
+augroup fugitive
+  autocmd!
+  autocmd BufNewFile,BufReadPost * call FugitiveDetect(expand('%:p'))
+  autocmd FileType           netrw call FugitiveDetect(fnamemodify(get(b:, 'netrw_curdir', @%), ':p'))
+  autocmd User NERDTreeInit,NERDTreeNewRoot call FugitiveDetect(b:NERDTree.root.path.str())
+  autocmd VimEnter * if expand('<amatch>')==''|call FugitiveDetect(getcwd())|endif
+  autocmd CmdWinEnter * call FugitiveDetect(expand('#:p'))
+  autocmd BufWinLeave * execute getwinvar(+bufwinnr(+expand('<abuf>')), 'fugitive_leave')
+augroup END
+
+" Section: Initialization
+
+function! fugitive#Init() abort
   if exists('#User#FugitiveBoot')
     try
       let [save_mls, &modelines] = [&mls, 0]
@@ -266,23 +275,20 @@ function! FugitiveDetect(path) abort
   finally
     let &mls = save_mls
   endtry
-  endif
+endfunction
+
+function! fugitive#is_git_dir(path) abort
+  return FugitiveIsGitDir(a:path)
+endfunction
+
+function! fugitive#extract_git_dir(path) abort
+  return FugitiveExtractGitDir(a:path)
 endfunction
 
 function! fugitive#detect(path) abort
   return FugitiveDetect(a:path)
 endfunction
 
-augroup fugitive
-  autocmd!
-  autocmd BufNewFile,BufReadPost * call FugitiveDetect(expand('%:p'))
-  autocmd FileType           netrw call FugitiveDetect(fnamemodify(get(b:, 'netrw_curdir', @%), ':p'))
-  autocmd User NERDTreeInit,NERDTreeNewRoot call FugitiveDetect(b:NERDTree.root.path.str())
-  autocmd VimEnter * if expand('<amatch>')==''|call FugitiveDetect(getcwd())|endif
-  autocmd CmdWinEnter * call FugitiveDetect(expand('#:p'))
-  autocmd BufWinLeave * execute getwinvar(+bufwinnr(+expand('<abuf>')), 'fugitive_leave')
-augroup END
-
 " Section: Repository
 
 let s:repo_prototype = {}