Add option to show only non-zero hunks

autoload/airline/extensions/hunks.vim

@@ -3,7 +3,14 @@
 
 function! airline#extensions#hunks#get_hunks()
   let hunks = GitGutterGetHunkSummary()
-  return printf('+%s ~%s -%s ', hunks[0], hunks[1], hunks[2])
+  let hunk_symbol = ['+', '~', '-']
+  let string = ''
+  for i in [0, 1, 2]
+    if g:airline_hunk_non_zero_only == 0 || hunks[i] > 0
+      let string .= printf('%s%s ', hunk_symbol[i], hunks[i])
+    endif
+  endfor
+  return string
 endfunction
 
 function! airline#extensions#hunks#init(ext)

doc/airline.txt

@@ -211,7 +211,9 @@ vim-gitgutter <https://github.com/airblade/vim-gitgutter>
 
 * enable/disable detecting changed hunks under source control. >
   let g:airline_enable_hunks = 1
-<
+
+* enable/disable showing only non-zero hunks.
+  let g:airline_hunk_non_zero_only = 0
 
 ==============================================================================
 FUNCREFS                                                  *airline-funcrefs*

plugin/airline.vim

@@ -25,6 +25,7 @@ call s:check_defined('g:airline_detect_iminsert', 0)
 call s:check_defined('g:airline_detect_modified', 1)
 call s:check_defined('g:airline_detect_paste', 1)
 call s:check_defined('g:airline_detect_whitespace', 1)
+call s:check_defined('g:airline_hunk_non_zero_only', 0)
 call s:check_defined('g:airline_branch_empty_message', '')
 call s:check_defined('g:airline_branch_prefix', exists('g:airline_powerline_fonts')?' ':'')
 call s:check_defined('g:airline_readonly_symbol', exists('g:airline_powerline_fonts')?'':'RO')