From dc22370cf1092ed7043d1cc1cda3ab0ec34bc91c Mon Sep 17 00:00:00 2001
From: chrox <chrox.huang@gmail.com>
Date: Sun, 10 Mar 2013 13:18:50 +0800
Subject: [PATCH] bugfix: intersected geom should be initiated with a fresh
 copy of self

---
 frontend/ui/geometry.lua | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/frontend/ui/geometry.lua b/frontend/ui/geometry.lua
index a20227d48..708186bad 100644
--- a/frontend/ui/geometry.lua
+++ b/frontend/ui/geometry.lua
@@ -117,7 +117,8 @@ returns a rectangle for the part that we and a given rectangle share
 TODO: what happens if there is no rectangle shared? currently behaviour is undefined.
 ]]--
 function Geom:intersect(rect_b)
-	local intersected = Geom:new(self)
+	-- make a copy of self
+	local intersected = self:copy()
 	if self.x < rect_b.x then
 		intersected.x = rect_b.x
 	end
@@ -259,6 +260,11 @@ function Geom:offsetWithin(rect_b, dx, dy)
 	end
 end
 
+function Geom:shrinkInside(rect_b, dx, dy)
+	self:offsetBy(dx, dy)
+	return self:intersect(rect_b)
+end
+
 --[[
 return the Euclidean distance between two geoms
 ]]--