解决方法:
1、下载GNU diff工具,注意安装依赖包。
1.1 Install GNU diff (http://gnuwin32.sourceforge.net/packages/diffutils.htm).
1.2 create a bat file (mydiff.bat) with the following content:
@echo off
<full path of the diff.exe installed in step 1> -U9999999 -L %3 -L %5 %6 %7
2、修改svn配置文件,路径:%appdata%\subversion\config,
In the SVN config file, add/edit the line:
diff-cmd = <full path of mydiff.bat>
3、现在再执行arc diff,就能显示上下文了。