From 186dada663e7dbe23546e4a5d57be31e690da292 Mon Sep 17 00:00:00 2001
From: Andy Stewart <boss@airbladesoftware.com>
Date: Thu, 5 Mar 2015 12:19:02 +0100
Subject: [PATCH] Warn when cursor not in a hunk.

---
 autoload/gitgutter.vim      | 50 +++++++++++++++++++++++--------------
 autoload/gitgutter/hunk.vim |  8 +++---
 2 files changed, 34 insertions(+), 24 deletions(-)

diff --git a/autoload/gitgutter.vim b/autoload/gitgutter.vim
index 83413f6..3693356 100644
--- a/autoload/gitgutter.vim
+++ b/autoload/gitgutter.vim
@@ -156,11 +156,15 @@ function! gitgutter#stage_hunk()
     " It doesn't make sense to stage a hunk otherwise.
     silent write
 
-    let diff_for_hunk = gitgutter#diff#generate_diff_for_hunk('stage')
-    call gitgutter#utility#system(gitgutter#utility#command_in_directory_of_file('git apply --cached --unidiff-zero - '), diff_for_hunk)
+    if empty(gitgutter#hunk#current_hunk())
+      call gitgutter#utility#warn('cursor is not in a hunk')
+    else
+      let diff_for_hunk = gitgutter#diff#generate_diff_for_hunk('stage')
+      call gitgutter#utility#system(gitgutter#utility#command_in_directory_of_file('git apply --cached --unidiff-zero - '), diff_for_hunk)
 
-    " refresh gitgutter's view of buffer
-    silent execute "GitGutter"
+      " refresh gitgutter's view of buffer
+      silent execute "GitGutter"
+    endif
 
     silent! call repeat#set("\<Plug>GitGutterStageHunk", -1)<CR>
   endif
@@ -172,11 +176,15 @@ function! gitgutter#revert_hunk()
     " It doesn't make sense to stage a hunk otherwise.
     silent write
 
-    let diff_for_hunk = gitgutter#diff#generate_diff_for_hunk('revert')
-    call gitgutter#utility#system(gitgutter#utility#command_in_directory_of_file('git apply --reverse --unidiff-zero - '), diff_for_hunk)
+    if empty(gitgutter#hunk#current_hunk())
+      call gitgutter#utility#warn('cursor is not in a hunk')
+    else
+      let diff_for_hunk = gitgutter#diff#generate_diff_for_hunk('revert')
+      call gitgutter#utility#system(gitgutter#utility#command_in_directory_of_file('git apply --reverse --unidiff-zero - '), diff_for_hunk)
 
-    " reload file
-    silent edit
+      " reload file
+      silent edit
+    endif
 
     silent! call repeat#set("\<Plug>GitGutterRevertHunk", -1)<CR>
   endif
@@ -186,19 +194,23 @@ function! gitgutter#preview_hunk()
   if gitgutter#utility#is_active()
     silent write
 
-    let diff_for_hunk = gitgutter#diff#generate_diff_for_hunk('preview')
+    if empty(gitgutter#hunk#current_hunk())
+      call gitgutter#utility#warn('cursor is not in a hunk')
+    else
+      let diff_for_hunk = gitgutter#diff#generate_diff_for_hunk('preview')
 
-    silent! wincmd P
-    if !&previewwindow
-      execute 'bo ' . &previewheight . ' new'
-      set previewwindow
+      silent! wincmd P
+      if !&previewwindow
+        execute 'bo ' . &previewheight . ' new'
+        set previewwindow
+      endif
+
+      setlocal noro modifiable filetype=diff buftype=nofile bufhidden=delete noswapfile
+      execute "%delete_"
+      call append(0, split(diff_for_hunk, "\n"))
+
+      wincmd p
     endif
-
-    setlocal noro modifiable filetype=diff buftype=nofile bufhidden=delete noswapfile
-    execute "%delete_"
-    call append(0, split(diff_for_hunk, "\n"))
-
-    wincmd p
   endif
 endfunction
 
diff --git a/autoload/gitgutter/hunk.vim b/autoload/gitgutter/hunk.vim
index e50516e..9d895d8 100644
--- a/autoload/gitgutter/hunk.vim
+++ b/autoload/gitgutter/hunk.vim
@@ -63,8 +63,8 @@ function! gitgutter#hunk#prev_hunk(count)
   endif
 endfunction
 
-" Returns the hunk the cursor is currently in or 0 if the cursor isn't in a
-" hunk.
+" Returns the hunk the cursor is currently in or an empty list if the cursor
+" isn't in a hunk.
 function! gitgutter#hunk#current_hunk()
   let current_hunk = []
 
@@ -75,9 +75,7 @@ function! gitgutter#hunk#current_hunk()
     endif
   endfor
 
-  if len(current_hunk) == 4
-    return current_hunk
-  endif
+  return current_hunk
 endfunction
 
 function! gitgutter#hunk#cursor_in_hunk(hunk)