[BUG] git-svn: does not work with tilde in repo URL

git svn does not work for me when tilde (~ or %7E) is present in a svn repository URL. Everything works as expected when I export the same repository on a URL without ~.

Test case 1:
% git svn clone -s --username michaelw http://svn.example.com/~michaelw/project/
Initialized empty Git repository in .git/
Using higher level of URL: http://svn.example.com/~michaelw/project => http://svn.example.com/%7Emichaelw/project
W: Ignoring error from SVN, path probably does not exist: (175002): RA  
layer request failed: REPORT request failed on '/~michaelw/project/! 
svn/bc/32': REPORT of '/~michaelw/project/!svn/bc/32': 200 OK (http://svn.example.com 
)
W: Do not be alarmed at the above message git-svn is just searching  
aggressively for old history.
This may take a while on large repositories
Path 'http:' was probably deleted:
RA layer request failed: REPORT request failed on '/~michaelw/project/! 
svn/bc/32': REPORT of '/~michaelw/project/!svn/bc/32': 200 OK (http://svn.example.com 
)
Will attempt to follow revisions r0 .. r32 committed before the deletion

Two things to note:
* In this case the svn-remote section in .git/config looks wrong, too:
[svn-remote "svn"]
	url = http://svn.example.com/%7Emichaelw/project
	fetch = http://svn.example.com/~michaelw/project/trunk:refs/remotes/trunk
	branches = http:/svn.example.com/~michaelw/project/branches/*:refs/ 
remotes/*
	tags = http:/svn.example.com/~michaelw/project/tags/*:refs/remotes/ 
tags/*

* The line "Path 'http:' was probably deleted:" apparently comes from  
the "http:" prefix in the URL.

Test case 2: % git svn clone -s --username michaelw http://svn.example.com/%7Emichaelw/project/ Initialized empty Git repository in .git/ Apache got a malformed URI: REPORT request failed on '/~michaelw/ project/!svn/vcc/default': Unusable URI: it does not refer to this repository at /Users/michaelw/sys/i686-apple-darwin9/bin/git-svn line 3837

(Both tests are with the patch from <20080418131204.GA53634@roadkill.foldr.org 
 > applied, so git-svn line numbers might be different.)

Cheers, Michael