Allow configuration of extra arguments for git-diff.

README.mkd

@@ -76,6 +76,7 @@ You can customise:
 * Whether or not the sign column is shown when there aren't any signs (defaults to no)
 * The signs' colours and symbols
 * Line highlights
+* Extra arguments for `git diff`
 * Whether or not vim-gitgutter is on initially (defaults to on)
 * Whether or not line highlighting is on initially (defaults to off)
 * Whether or not vim-gitgutter runs on `BufEnter` (defaults to yes)
@@ -134,6 +135,14 @@ GitGutterDeleteLine       " default: links to DiffDelete
 GitGutterChangeDeleteLine " default: links to GitGutterChangeLineDefault, i.e. DiffChange
 ```
 
+#### Extra arguments for `git diff`
+
+If you want to pass extra arguments to `git diff`, for example to ignore whitespace, do so like this:
+
+```viml
+let g:gitgutter_diff_args = '-w'
+```
+
 #### To turn off vim-gitgutter by default
 
 Add `let g:gitgutter_enabled = 0` to your `~/.vimrc`.

doc/gitgutter.txt

@@ -94,6 +94,7 @@ You can customise:
 - The sign column's colours
 - The signs' colours and symbols
 - Line highlights
+- Extra arguments for git-diff
 - Whether or not vim-gitgutter is on initially (defaults to on)
 - Whether or not line highlighting is on initially (defaults to off)
 - Whether or not vim-gitgutter runs on `BufEnter` (defaults to yes)
@@ -165,6 +166,13 @@ colorscheme or |vimrc|:
   GitGutterChangeDeleteLine " default: links to GitGutterChangeLineDefault
 <
 
+EXTRA ARGUMENTS FOR GIT-DIFF
+
+To pass extra arguments to git-diff, add this to your |vimrc|:
+>
+  let g:gitgutter_diff_args = '-w'
+<
+
 TO TURN OFF VIM-GITGUTTER BY DEFAULT
 
 Add to your |vimrc|

plugin/gitgutter.vim

@@ -25,6 +25,7 @@ call s:set('g:gitgutter_sign_added', '+')
 call s:set('g:gitgutter_sign_modified', '~')
 call s:set('g:gitgutter_sign_removed', '_')
 call s:set('g:gitgutter_sign_modified_removed', '~_')
+call s:set('g:gitgutter_diff_args', '')
 
 let s:file = ''
 
@@ -173,7 +174,6 @@ function! s:define_sign_text_highlights()
   sign define GitGutterLineModifiedRemoved texthl=GitGutterChangeDelete
 endfunction
 
-
 function! s:define_sign_line_highlights()
   if s:highlight_lines
     sign define GitGutterLineAdded           linehl=GitGutterAddLine
@@ -194,8 +194,8 @@ endfunction
 " Diff processing {{{
 
 function! s:run_diff()
-  let cmd = 'git diff --no-ext-diff --no-color -U0 ' . shellescape(s:file()) .
+  let cmd = 'git diff --no-ext-diff --no-color -U0 ' . g:gitgutter_diff_args . ' ' .
-        \ ' | grep -e "^@@ "'
+        \ shellescape(s:file()) .  ' | grep -e "^@@ "'
   let diff = system(s:command_in_directory_of_file(cmd))
   return diff
 endfunction