From c4d0b44346633ac550bdade512c7fd178396c92a Mon Sep 17 00:00:00 2001
From: "Yixiang (Sean) Lu" <yxlu@yxlu-macpro.roam.corp.google.com>
Date: Wed, 5 Oct 2016 15:14:18 -0700
Subject: [PATCH] Fixed a index out of bound error when trying to delete the
 first line of a document.

---
 XVim/NSTextStorage+VimOperation.m | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/XVim/NSTextStorage+VimOperation.m b/XVim/NSTextStorage+VimOperation.m
index 2214e9c3..87fda110 100644
--- a/XVim/NSTextStorage+VimOperation.m
+++ b/XVim/NSTextStorage+VimOperation.m
@@ -253,7 +253,7 @@ - (NSUInteger)xvim_firstOfLine:(NSUInteger)index
         return NSNotFound;
     }
 
-    if (pos == index && isNewline([self.xvim_string characterAtIndex:(pos - 1)])) {
+    if (pos == index && pos > 0 && isNewline([self.xvim_string characterAtIndex:(pos - 1)])) {
         return NSNotFound;
     }
     return pos;