"svn copy --parents" allows insertion of an errant '\' in http://path

Hi,

I pulled a silly mistake just now... I accidentally let my windows
backslash enter into an http URL during an SVN copy operation.

copy --parents "C:\Project_files\sandbox\bar.c" "
http://svr/sandbox/A\B/bar1.c" -m "bad commit"

It successfully committed.

svn update now returns the following:

svn: E155000: 'A\B' is not a valid filename in directory
'C:\Project_files\sandbox\'

First, I assume there should be a check to prevent this invalid character
for URLs. Second, how do I undo my error?

I'm on SVN 1.8.5 and the backslash should give me away as a windows user
(Win7 - 64bit).

Thanks for the help,
Dan