Add g:gitgutter_terminal_reports_focus to enable FocusGained workaround.

See #490.

README.mkd

@@ -24,7 +24,7 @@ Features:
 Constraints:
 
 * Supports git only.  If you work with other version control systems, I recommend [vim-signify](https://github.com/mhinz/vim-signify).
-* Relies on the `FocusGained` event.  If your terminal doesn't report focus events, I suggest using something like [Terminus][].
+* Relies on the `FocusGained` event.  If your terminal doesn't report focus events, either use something like [Terminus][] or set `let g:gitgutter_terminal_reports_focus=0`.
 
 
 ### Screenshot
@@ -506,7 +506,7 @@ Here are some things you can check:
 
 #### When signs don't update after focusing Vim
 
-* Your terminal probably isn't reporting focus events.  Try installing [Terminus][].
+* Your terminal probably isn't reporting focus events.  Either try installing [Terminus][] or set `let g:gitgutter_terminal_reports_focus=0`.
 
 
 ### Shameless Plug

doc/gitgutter.txt

@@ -252,6 +252,10 @@ Signs:~
     |g:gitgutter_sign_column_always|
     |g:gitgutter_override_sign_column_highlight|
 
+Terminal:~
+
+    |g:gitgutter_terminal_reports_focus|
+
 General:~
 
     |g:gitgutter_enabled|
@@ -365,6 +369,22 @@ it in your |vimrc|:
   User-defined (terminal Vim)         highlight SignColumn ctermbg={whatever}
   User-defined (graphical Vim)        highlight SignColumn guibg={whatever}
 
+
+                                           *g:gitgutter_terminal_reports_focus*
+Default: 1
+
+Normally the plugin uses |FocusGained| to force-update all buffers when Vim
+receives focus.  However some terminals do not report focus events and so the
+|FocusGained| autocommand never fires.
+
+If this applies to you, either install something like Terminus
+(https://github.com/wincent/terminus) to make |FocusGained| work or set this
+option to 0.
+
+When this option is 0, the plugin force-updates the buffer on |BufEnter|
+(instead of only updating if the buffer's contents has changed since the last
+update).
+
                                                           *g:gitgutter_enabled*
 Default: 1
 
@@ -491,6 +511,9 @@ Try reducing 'updatetime':
 
 When signs don't update after focusing Vim:~
 
-Your terminal probably isn't reporting focus events.  Try installing Terminus
-(https://github.com/wincent/terminus).
+Your terminal probably isn't reporting focus events.  Either try installing
+Terminus (https://github.com/wincent/terminus) or set:
+>
+    let g:gitgutter_terminal_reports_focus = 0
+<
 

plugin/gitgutter.vim

@@ -48,6 +48,7 @@ call s:set('g:gitgutter_sign_modified_removed',    '~_')
 call s:set('g:gitgutter_diff_args',                  '')
 call s:set('g:gitgutter_diff_base',                  '')
 call s:set('g:gitgutter_map_keys',                    1)
+call s:set('g:gitgutter_terminal_reports_focus',      1)
 call s:set('g:gitgutter_async',                       1)
 call s:set('g:gitgutter_log',                         0)
 
@@ -209,10 +210,10 @@ augroup gitgutter
   autocmd BufEnter *
         \ if exists('t:gitgutter_didtabenter') && t:gitgutter_didtabenter |
         \   let t:gitgutter_didtabenter = 0 |
-        \   call gitgutter#all(0) |
+        \   call gitgutter#all(!g:gitgutter_terminal_reports_focus) |
         \ else |
         \   call gitgutter#init_buffer(bufnr('')) |
-        \   call gitgutter#process_buffer(bufnr(''), 0) |
+        \   call gitgutter#process_buffer(bufnr(''), !g:gitgutter_terminal_reports_focus) |
         \ endif
 
   autocmd CursorHold,CursorHoldI            * call gitgutter#process_buffer(bufnr(''), 0)