Add vimagit extension

autoload/airline/extensions.vim

@@ -183,6 +183,12 @@ function! airline#extensions#load()
     call add(loaded_ext, 'hunks')
   endif
 
+  if get(g:, 'airline#extensions#vimagit#enabled', 1)
+        \ && (exists('g:loaded_magit'))
+    call airline#extensions#vimagit#init(s:ext)
+    call add(loaded_ext, 'vimagit')
+  endif
+
   if get(g:, 'airline#extensions#tagbar#enabled', 1)
         \ && exists(':TagbarToggle')
     call airline#extensions#tagbar#init(s:ext)

autoload/airline/extensions/vimagit.vim

@@ -0,0 +1,30 @@
+" MIT License. Copyright (c) 2016 Jerome Reybert
+" vim: et ts=2 sts=2 sw=2
+
+" This plugin replace the whole section_a when in vimagit buffer
+scriptencoding utf-8
+
+if !get(g:, 'loaded_magit', 0)
+  finish
+endif
+
+function! airline#extensions#vimagit#init(ext)
+  call a:ext.add_statusline_func('airline#extensions#vimagit#apply')
+endfunction
+
+function! airline#extensions#vimagit#get_mode()
+	if ( b:magit_current_commit_mode == '' )
+		return "STAGING"
+	elseif ( b:magit_current_commit_mode == 'CC' )
+		return "COMMIT"
+	elseif ( b:magit_current_commit_mode == 'CA' )
+		return "AMEND"
+	else
+		return "???"
+endfunction
+
+function! airline#extensions#vimagit#apply(...)
+  if ( &filetype == 'magit' )
+    let w:airline_section_a = '%{airline#extensions#vimagit#get_mode()}'
+  endif
+endfunction