清理
也许由于服务器问题，一个Subversion指令不能成功地完成，你的工作副本因此被滞留在一个不一致的状态。 那样的话，你需要在该目录上使用 → 命令。在工作副本的根目录使用它是一个好主意。
Cleanup
has another useful side effect. If a file date changes but its content
doesn't, Subversion cannot tell whether it has really changed except by
doing a byte-by-byte comparison with the pristine copy. If you have a
lot of files in this state it makes acquiring status very slow, which
will make many dialogs slow to respond. Executing a Cleanup on your
working copy will repair these “broken” timestamps and restore status checks to full speed.
使用提交时戳
Subversion的一些早期发布中存在一个bug，当你使用使用提交时戳选项检出的时候会造成时戳混乱。使用清理命令可以修正工作副本中的这些问题。