From 44d7d6cd2963d58168e2dcd84f3fe81d1e6336e5 Mon Sep 17 00:00:00 2001
From: Qingping Hou <dave2008713@gmail.com>
Date: Mon, 19 Mar 2012 20:43:52 +0800
Subject: [PATCH] fix: handle -1 index when deleting characters in inputbox

---
 inputbox.lua | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/inputbox.lua b/inputbox.lua
index 65321e0d6..e30e88507 100644
--- a/inputbox.lua
+++ b/inputbox.lua
@@ -60,11 +60,13 @@ function InputBox:delChar()
 		return
 	end
 
+	local cur_index = (self.cursor.x_pos + 3 - self.input_start_x)
+						/ self.fwidth
+	if cur_index == 0 then return end
+
 	self.cursor:clear()
 
 	-- draw new text
-	local cur_index = (self.cursor.x_pos + 3 - self.input_start_x)
-						/ self.fwidth
 	self.input_string = self.input_string:sub(0,cur_index-1)..
 						self.input_string:sub(cur_index+1, -1)
 	self:refreshText()