Support extensions.worktreeConfig

Resolves: #1898

Author: tpope

plugin/fugitive.vim

@@ -344,22 +344,32 @@ function! s:Tree(path) abort
   endif
   if !has_key(s:worktree_for_dir, dir)
     let s:worktree_for_dir[dir] = ''
+    let ext_wtc_pat = 'v:val =~# "^\\s*worktreeConfig *= *\\%(true\\|yes\\|on\\|1\\) *$"'
     let config = s:ReadFile(dir . '/config', 10)
     if len(config)
-      let wt_config = filter(copy(config),'v:val =~# "^\\s*worktree *="')
-      if len(wt_config) == 1
-        let worktree = FugitiveVimPath(matchstr(wt_config[0], '= *\zs.*'))
-      else
-        call filter(config,'v:val =~# "^\\s*bare *= *true *$"')
-        if empty(config)
-          let s:worktree_for_dir[dir] = 0
-        endif
+      let ext_wtc_config = filter(copy(config), ext_wtc_pat)
+      if len(ext_wtc_config) == 1 && filereadable(dir . '/config.worktree')
+         let config += s:ReadFile(dir . '/config.worktree', 10)
       endif
     else
       let worktree = fnamemodify(FugitiveVimPath(get(s:ReadFile(dir . '/gitdir', 1), '0', '')), ':h')
       if worktree ==# '.'
         unlet! worktree
       endif
+      if len(filter(s:ReadFile(FugitiveCommonDir(dir) . '/config', 10), ext_wtc_pat))
+        let config = s:ReadFile(dir . '/config.worktree', 10)
+      endif
+    endif
+    if len(config)
+      let wt_config = filter(copy(config), 'v:val =~# "^\\s*worktree *="')
+      if len(wt_config)
+        let worktree = FugitiveVimPath(matchstr(wt_config[0], '= *\zs.*'))
+      elseif !exists('worktree')
+        call filter(config,'v:val =~# "^\\s*bare *= *true *$"')
+        if empty(config)
+          let s:worktree_for_dir[dir] = 0
+        endif
+      endif
     endif
     if exists('worktree')
       let s:worktree_for_dir[dir] = s:Slash(resolve(worktree))