Enhance fugitive#Prepare()

autoload/fugitive.vim

@@ -204,17 +204,23 @@ function! s:Tree(...) abort
   return FugitiveTreeForGitDir(a:0 ? a:1 : get(b:, 'git_dir', ''))
 endfunction
 
-function! s:PreparePathArgs(cmd, dir) abort
-  if fugitive#GitVersion() !~# '^[01]\.'
+function! s:PreparePathArgs(cmd, dir, literal) abort
+  let literal_supported = fugitive#GitVersion() !~# '^0\|^1\.[1-8]\.'
+  if a:literal && literal_supported
     call insert(a:cmd, '--literal-pathspecs')
   endif
   let split = index(a:cmd, '--')
-  let tree = s:Tree(a:dir)
-  if empty(tree) || split < 0
+  if split < 0
     return a:cmd
   endif
   for i in range(split + 1, len(a:cmd) - 1)
-    let a:cmd[i] = fugitive#Path(a:cmd[i], './', a:dir)
+    if type(a:cmd[i]) == type(0)
+      let a:cmd[i] = fugitive#Path(bufname(a:cmd[i]), './', a:dir)
+    elseif a:literal
+      let a:cmd[i] = fugitive#Path(a:cmd[i], './', a:dir)
+    elseif !literal_supported
+      let a:cmd[i] = substitute(a:cmd[i], '^:\%(/\|([^)]*)\)\=:\=', './', '')
+    endif
   endfor
   return a:cmd
 endfunction
@@ -222,7 +228,7 @@ endfunction
 function! s:TreeChomp(...) abort
   let args = copy(type(a:1) == type([]) ? a:1 : a:000)
   let dir = a:0 > 1 && type(a:1) == type([]) ? a:2 : b:git_dir
-  call s:PreparePathArgs(args, dir)
+  call s:PreparePathArgs(args, dir, 1)
   let tree = s:Tree(dir)
   let pre = ''
   if empty(tree)
@@ -238,15 +244,66 @@ function! s:TreeChomp(...) abort
         \ join(map(args, 's:shellesc(v:val)'))), '\n$', '')
 endfunction
 
-function! fugitive#Prepare(cmd, ...) abort
-  let dir = a:0 ? a:1 : get(b:, 'git_dir', '')
-  let tree = s:Tree(dir)
-  let args = type(a:cmd) == type([]) ? join(map(s:PreparePathArgs(copy(a:cmd), dir), 's:shellesc(v:val)')) : a:cmd
+let s:prepare_env = {
+      \ 'sequence.editor': 'GIT_SEQUENCE_EDITOR',
+      \ 'core.editor': 'GIT_EDITOR',
+      \ 'core.askpass': 'GIT_ASKPASS',
+      \ }
+function! fugitive#Prepare(...) abort
+  if !a:0
+    return g:fugitive_git_executable
+  endif
+  if type(a:1) ==# type([])
+    let cmd = a:000[1:-1] + a:1
+  else
+    let cmd = copy(a:000)
+  endif
   let pre = ''
-  if empty(tree) || (type(a:cmd) == type([]) && index(a:cmd, '--') == len(a:cmd) - 1)
+  let i = 0
+  while i < len(cmd)
+    if cmd[i] =~# '^$\|[\/.]' && cmd[i] !~# '^-'
+      let dir = remove(cmd, 0)
+    elseif type(cmd[i]) ==# type(0)
+      let dir = getbufvar(remove(cmd, i), 'git_dir')
+    elseif cmd[i] ==# '-c' && len(cmd) > i + 1
+      let key = matchstr(cmd[i+1], '^[^=]*')
+      if has_key(s:prepare_env, tolower(key)) || key !~# '\.'
+        let var = get(s:prepare_env, tolower(key), key)
+        let val = matchstr(cmd[i+1], '=\zs.*')
+        if s:winshell()
+          let pre .= 'set ' . var . '=' . s:shellesc(val) . ' & '
+        else
+          let pre = (len(pre) ? pre : 'env ') . var . '=' . s:shellesc(val) . ' '
+        endif
+      endif
+      if fugitive#GitVersion() =~# '^0\|^1\.[1-7]\.' || cmd[i+1] !~# '\.'
+        call remove(cmd, i, i + 1)
+      else
+        let i += 2
+      endif
+    elseif cmd[i] =~# '^--.*pathspecs$'
+      let explicit_pathspec_option = 1
+      if fugitive#GitVersion() =~# '^0\|^1\.[1-8]\.'
+        call remove(cmd, i)
+      else
+        let i += 1
+      endif
+    elseif cmd[i] !~# '^-'
+      break
+    else
+      let i += 1
+    endif
+  endwhile
+  if !exists('dir')
+    let dir = get(b:, 'git_dir', '')
+  endif
+  let tree = s:Tree(dir)
+  call s:PreparePathArgs(cmd, dir, !exists('explicit_pathspec_option'))
+  let args = join(map(copy(cmd), 's:shellesc(v:val)'))
+  if empty(tree) || index(cmd, '--') == len(cmd) - 1
     let args = s:shellesc('--git-dir=' . dir) . ' ' . args
-  elseif fugitive#GitVersion() =~# '^[01]\.'
-    let pre = 'cd ' . s:shellesc(tree) . (s:winshell() ? ' & ' : '; ')
+  elseif fugitive#GitVersion() =~# '^0\|^1\.[1-8]\.'
+    let pre = 'cd ' . s:shellesc(tree) . (s:winshell() ? ' & ' : '; ') . pre
   else
     let args = '-C ' . s:shellesc(tree) . ' ' . args
   endif
@@ -377,6 +434,10 @@ endfunction
 
 call s:add_methods('repo',['dir','tree','bare','route','translate','head'])
 
+function! s:repo_prepare(...) dict abort
+  return call('fugitive#Prepare', [self.git_dir] + a:000)
+endfunction
+
 function! s:repo_git_command(...) dict abort
   let git = s:UserCommand() . ' --git-dir='.s:shellesc(self.git_dir)
   return git.join(map(copy(a:000),'" ".s:shellesc(v:val)'),'')
@@ -401,7 +462,7 @@ function! s:repo_rev_parse(rev) dict abort
   return fugitive#RevParse(a:rev, self.git_dir)
 endfunction
 
-call s:add_methods('repo',['git_command','git_chomp','git_chomp_in_tree','rev_parse'])
+call s:add_methods('repo',['prepare','git_command','git_chomp','git_chomp_in_tree','rev_parse'])
 
 function! s:repo_superglob(base) dict abort
   return map(fugitive#Complete(a:base, self.git_dir), 'substitute(v:val, ''\\\(.\)'', ''\1'', "g")')