From d420a445363bef98dc50fd622c5c96b202abd605 Mon Sep 17 00:00:00 2001
From: Andy Stewart <boss@airbladesoftware.com>
Date: Tue, 7 Jan 2014 13:34:21 +0100
Subject: [PATCH] Reduce duplicate work due to overlapping autocommands.

---
 README.mkd           | 18 ++++++-----
 plugin/gitgutter.vim | 75 ++++++++++++++++++++++++++++----------------
 2 files changed, 58 insertions(+), 35 deletions(-)

diff --git a/README.mkd b/README.mkd
index fc9ac2d..ab49532 100644
--- a/README.mkd
+++ b/README.mkd
@@ -74,12 +74,12 @@ See the customisation section below for how to change the defaults.
 
 By default the signs are updated when you:
 
-* Stop typing
-* Change buffer
-* Change tab
-* Save a buffer
-* Change a file outside Vim
-* Focus the GUI.
+* Stop typing (realtime)
+* Change buffer (eager)
+* Change tab (eager)
+* Save a buffer (always)
+* Change a file outside Vim (always)
+* Focus the GUI (eager but not gVim on Windows).
 
 This can cause a noticeable lag on some systems so you can configure the plugin to update less often.  See the customisation section below.
 
@@ -200,7 +200,7 @@ let g:gitgutter_realtime = 0
 
 #### To stop vim-gitgutter running eagerly
 
-By default the plugin also runs every time you read a file, on `BufEnter`, `TabEnter` and `FocusGained`.
+By default the plugin also runs on `BufEnter` (to notice `git add` outside vim), `TabEnter` and `FocusGained`.
 
 This can cause a noticeable lag for some people so you can set the plugin to run instead only when you read or write a file.
 
@@ -210,7 +210,9 @@ To turn off eager execution, add this to your `~/.vimrc`:
 let g:gitgutter_eager = 0
 ```
 
-Note that `FocusGained` cannot be used with gVim on Windows due to a Vim/shell bug causing an infinite loop.
+Note that `FocusGained` is not activated in gVim on Windows due to a Vim/shell bug causing an infinite loop.
+
+The plugin always runs on `FileChangedShellPost` to notice `git stash` outside vim.
 
 
 ### FAQ
diff --git a/plugin/gitgutter.vim b/plugin/gitgutter.vim
index ff9d007..22e346f 100644
--- a/plugin/gitgutter.vim
+++ b/plugin/gitgutter.vim
@@ -38,38 +38,51 @@ call highlight#define_signs()
 " Public interface {{{
 
 function! GitGutterAll()
-  for buffer_id in tabpagebuflist() 
-    call GitGutter(expand('#' . buffer_id . ':p'))
+  for buffer_id in tabpagebuflist()
+    let file = expand('#' . buffer_id . ':p')
+    if !empty(file)
+      call GitGutter(file, 0, 0)
+    endif
   endfor
 endfunction
 command GitGutterAll call GitGutterAll()
 
-" Supply optional argument to use realtime mode.
-function! GitGutter(file, ...)
-  call utility#set_file(a:file)
-  if utility#is_active()
-    if (a:0 == 1) || utility#has_unsaved_changes(a:file)
-      let diff = diff#run_diff(1)
-    else
-      let diff = diff#run_diff(0)
-    endif
-    let s:hunks = diff#parse_diff(diff)
-    let modified_lines = diff#process_hunks(s:hunks)
-    if g:gitgutter_sign_column_always
-      call sign#add_dummy_sign()
-    else
-      if utility#differences(s:hunks)
-        call sign#add_dummy_sign()  " prevent flicker
+" Does the actual work.
+"
+" file: (string) the file to process.
+" realtime: (boolean) when truthy, do a realtime diff; otherwise do a disk-based diff.
+" fresh_changes: (boolean) when truthy, only process if there are buffer changes
+" since the last gitgutter process; otherwise always process.
+function! GitGutter(file, realtime, fresh_changes)
+  if !a:fresh_changes || getbufvar(a:file, 'changedtick') != getbufvar(a:file, 'gitgutter_last_tick', -1)
+
+    call utility#set_file(a:file)
+    if utility#is_active()
+      if a:realtime || utility#has_unsaved_changes(a:file)
+        let diff = diff#run_diff(1)
       else
-        call sign#remove_dummy_sign()
+        let diff = diff#run_diff(0)
       endif
+      let s:hunks = diff#parse_diff(diff)
+      let modified_lines = diff#process_hunks(s:hunks)
+      if g:gitgutter_sign_column_always
+        call sign#add_dummy_sign()
+      else
+        if utility#differences(s:hunks)
+          call sign#add_dummy_sign()  " prevent flicker
+        else
+          call sign#remove_dummy_sign()
+        endif
+      endif
+      call sign#update_signs(a:file, modified_lines)
+    else
+      call hunk#reset()
     endif
-    call sign#update_signs(a:file, modified_lines)
-  else
-    call hunk#reset()
+
+    call setbufvar(a:file, 'gitgutter_last_tick', getbufvar(a:file, 'changedtick'))
   endif
 endfunction
-command GitGutter call GitGutter(utility#current_file())
+command GitGutter call GitGutter(utility#current_file(), 0, 0)
 
 function! GitGutterDisable()
   let g:gitgutter_enabled = 0
@@ -189,18 +202,26 @@ augroup gitgutter
   autocmd!
 
   if g:gitgutter_realtime
-    autocmd CursorHold,CursorHoldI * call GitGutter(utility#current_file(), 1)
+    autocmd CursorHold,CursorHoldI * call GitGutter(utility#current_file(), 1, 1)
   endif
 
   if g:gitgutter_eager
-    autocmd BufEnter,BufWritePost,FileWritePost,FileChangedShellPost * call GitGutter(utility#current_file())
-    autocmd TabEnter * call GitGutterAll()
+    autocmd BufEnter,BufWritePost,FileChangedShellPost *
+          \  if gettabvar(tabpagenr(), 'gitgutter_didtabenter')
+          \|   call settabvar(tabpagenr(), 'gitgutter_didtabenter', 0)
+          \| else
+          \|   call GitGutter(utility#current_file(), 0, 0)
+          \| endif
+    autocmd TabEnter *
+          \  call settabvar(tabpagenr(), 'gitgutter_didtabenter', 1)
+          \| call GitGutterAll()
     if !has('gui_win32')
       autocmd FocusGained * call GitGutterAll()
     endif
   else
-    autocmd BufReadPost,BufWritePost,FileReadPost,FileWritePost,FileChangedShellPost * call GitGutter(utility#current_file())
+    autocmd BufRead,BufWritePost,FileChangedShellPost * call GitGutter(utility#current_file())
   endif
+
   autocmd ColorScheme * call highlight#define_sign_column_highlight() | call highlight#define_highlights()
 augroup END