too man macvim applet in docky while using gvimdiff as svn diff tool

i am using gvimdiff tool for svn diff:
svn_diff

#!/bin/bash

svn diff --diff-cmd diffwrap.sh "$@" 2>/dev/null

diffwrap.sh

#!/bin/bash

gvimdiff $6 $7

svn status:

M       trunk/main/main.cpp
M       trunk/principle/dllmain.cpp

while i type svn_diff in terminal, the terminal show:

Index: trunk/main/main.cpp
===================================================================
Index: trunk/principle/dllmain.cpp
===================================================================
2 files to edit
2 files to edit 

two diff files open(two macvim window show, and a new macvim applet shows in docky).
how to get one diff file and one macvim window per times ? that is, while i type svn_diff in terminal,
the terminal show:

Index: trunk/main/main.cpp
===================================================================

and i quit the macvim, next time, it show

Index: trunk/principle/dllmain.cpp
===================================================================

and one new macvim show simultaneously.
in the end, while finished svn_diff(:qa in gvim_diff per diff), two macvim applet in docky, on is default i put, another is a new one. every time i execute svn_diff, always a new macvim is stick to the docky if i do not quit it.

使用多个已修改文件运行提到的 svn_diff 和 diffwrap.sh 脚本来重现问题，然后检查 gvimdiff 如何启动 MacVim 窗口和 dock 小程序。完成的标准是连续的 diff 使用同一个 MacVim 窗口，并且会话结束后不会留下额外的 dock 小程序。