From 3420cbf6cb75c95e169a58d578c95e7da59a9b35 Mon Sep 17 00:00:00 2001
From: Andy Stewart <boss@airbladesoftware.com>
Date: Tue, 10 Mar 2015 10:17:34 +0100
Subject: [PATCH] Preserve alternate buffer when processing realtime diff.

See #238.
---
 autoload/gitgutter/diff.vim |  2 +-
 test/helper.vim             |  5 +++++
 test/keepAlt.expected       |  3 +++
 test/testKeepAlt.vim        | 12 ++++++++++++
 4 files changed, 21 insertions(+), 1 deletion(-)
 create mode 100644 test/keepAlt.expected
 create mode 100644 test/testKeepAlt.vim

diff --git a/autoload/gitgutter/diff.vim b/autoload/gitgutter/diff.vim
index 01b447b..1e02662 100644
--- a/autoload/gitgutter/diff.vim
+++ b/autoload/gitgutter/diff.vim
@@ -30,7 +30,7 @@ function! gitgutter#diff#run_diff(realtime, use_external_grep)
       let buff_file .= '.'.extension
     endif
     let cmd .= 'git show '.blob_name.' > '.blob_file.' && '
-    execute 'silent write' buff_file
+    execute 'keepalt silent write' buff_file
   endif
 
   let cmd .= 'git diff --no-ext-diff --no-color -U0 '.g:gitgutter_diff_args.' -- '
diff --git a/test/helper.vim b/test/helper.vim
index 003a2ac..aaccf39 100644
--- a/test/helper.vim
+++ b/test/helper.vim
@@ -20,3 +20,8 @@ function! DumpGitDiffStaged(filename)
   call system('git diff --staged fixture.txt > '.a:filename.'.actual')
 endfunction
 
+function! Dump(text, filename)
+  let msg = type(a:text) == 1 ? split(a:text, '\n') : a:text
+  call writefile(msg, a:filename.'.actual', 'a')
+endfunction
+
diff --git a/test/keepAlt.expected b/test/keepAlt.expected
new file mode 100644
index 0000000..feee7b5
--- /dev/null
+++ b/test/keepAlt.expected
@@ -0,0 +1,3 @@
+buffer: fixture.txt
+altbuffer: 
+altbuffer: 
diff --git a/test/testKeepAlt.vim b/test/testKeepAlt.vim
new file mode 100644
index 0000000..303ff0f
--- /dev/null
+++ b/test/testKeepAlt.vim
@@ -0,0 +1,12 @@
+source helper.vim
+call Setup()
+
+enew
+execute "normal! \<C-^>"
+call Dump('buffer: '.bufname(''), 'keepAlt')
+call Dump('altbuffer: '.bufname('#'), 'keepAlt')
+
+normal ggx
+doautocmd CursorHold
+call Dump('altbuffer: '.bufname('#'), 'keepAlt')
+