From 4c6aa4401b6e06d5f4863505c56af7eca3b7d41b Mon Sep 17 00:00:00 2001
From: Bailey Ling <bling@live.ca>
Date: Sun, 8 Sep 2013 14:03:49 +0000
Subject: [PATCH] check the git/hg root when changing buffers. resolves #237.

---
 autoload/airline/extensions/branch.vim | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/autoload/airline/extensions/branch.vim b/autoload/airline/extensions/branch.vim
index 0aa3da5..8a83a31 100644
--- a/autoload/airline/extensions/branch.vim
+++ b/autoload/airline/extensions/branch.vim
@@ -27,12 +27,24 @@ function! airline#extensions#branch#get_head()
     endif
   endif
 
-  return empty(head)
+  return empty(head) || !s:check_in_path()
         \ ? s:empty_message
         \ : printf('%s%s', empty(s:symbol) ? '' : s:symbol.' ', head)
 endfunction
 
-function! airline#extensions#branch#init(ext)
-  call airline#parts#define_function('branch', 'airline#extensions#branch#get_head')
+function! s:check_in_path()
+  if !exists('b:airline_branch_path')
+    let root = get(b:, 'git_dir', get(b:, 'mercurial_dir', ''))
+    let bufferpath = resolve(fnamemodify(expand('%'), ':p:h'))
+    let root = fnamemodify(root, ':h')
+    let b:airline_file_in_root = stridx(bufferpath, root) > -1
+  endif
+  return b:airline_file_in_root
+endfunction
+
+function! airline#extensions#branch#init(ext)
+  call airline#parts#define_function('branch', 'airline#extensions#branch#get_head')
+
+  autocmd BufReadPost * unlet! b:airline_file_in_root
 endfunction