From d85d697b5fa086eb86736a45dee96026010e0646 Mon Sep 17 00:00:00 2001
From: Marco Hinz <mh.codebro@gmail.com>
Date: Fri, 15 Jan 2016 13:05:01 +0100
Subject: [PATCH] Hunks: make s:source_func local to buffer

Prior to this change airline set the function for getting hunks only once,
which works as long as you don't use simlar plugins for different VCS at the
same time.

If that was the case, only one plugin would have won, depending on the first
buffer handled by these plugins. And although the code for the other plugin
was run every time, you would never see the actual line changes, since airline
didn't even bother checking.

Now these plugins can be used side-by-side in the same Vim instance, e.g.
gitgutter for, well, git and signify for the rest.
---
 autoload/airline/extensions/hunks.vim | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/autoload/airline/extensions/hunks.vim b/autoload/airline/extensions/hunks.vim
index 028c5e7..86d8655 100644
--- a/autoload/airline/extensions/hunks.vim
+++ b/autoload/airline/extensions/hunks.vim
@@ -44,22 +44,21 @@ function! s:get_hunks_empty()
   return ''
 endfunction
 
-let s:source_func = ''
 function! s:get_hunks()
-  if empty(s:source_func)
-    if get(g:, 'loaded_signify', 0)
-      let s:source_func = 's:get_hunks_signify'
+  if !exists('b:source_func')
+    if get(g:, 'loaded_signify') && sy#buffer_is_active()
+      let b:source_func = 's:get_hunks_signify'
     elseif exists('*GitGutterGetHunkSummary')
-      let s:source_func = 's:get_hunks_gitgutter'
+      let b:source_func = 's:get_hunks_gitgutter'
     elseif exists('*changes#GetStats')
-      let s:source_func = 's:get_hunks_changes'
+      let b:source_func = 's:get_hunks_changes'
     elseif exists('*quickfixsigns#vcsdiff#GetHunkSummary')
-      let s:source_func = 'quickfixsigns#vcsdiff#GetHunkSummary'
+      let b:source_func = 'quickfixsigns#vcsdiff#GetHunkSummary'
     else
-      let s:source_func = 's:get_hunks_empty'
+      let b:source_func = 's:get_hunks_empty'
     endif
   endif
-  return {s:source_func}()
+  return {b:source_func}()
 endfunction
 
 function! airline#extensions#hunks#get_hunks()