[BUG] no way to delete file external (Subversion 1.6.x)

Hello,

I found no way to delete file external once svn:externals property has
been set (not committed) and update performed once. See attached
reproduction script for details.

I think update should remove file external when its definition is
removed from svn:externals property. What do you think on that?

-- 
Alexander Kitaev,
TMate Software,
http://svnkit.com/ - Java [Sub]Versioning Library!
http://sqljet.com/ - Java SQLite Library!

#!/bin/sh

# The next line is the only line you should need to adjust.
SVNDIR=/home/builder/usr/svn-16x/bin

SVN=${SVNDIR}/svn
SVNSERVE=${SVNDIR}/svnserve
SVNADMIN=${SVNDIR}/svnadmin

URL=file:///`pwd`/repos

rm -rf repos wc import-me

${SVNADMIN} create repos

echo "### Making a Greek Tree for import..."
mkdir import-me
mkdir import-me/dir
touch import-me/dir/file.txt

(cd import-me; ${SVN} import -q -m "Initial import." ${URL})

echo "### Checking out WC..."
${SVN} co ${URL} wc

echo "### Setting svn:externals property..."
${SVN} ps svn:externals "external.txt ${URL}/dir/file.txt" wc/dir

echo "### Update working copy to get file external..."
${SVN} up wc

echo "### Delete svn:externals property..."
${SVN} pd svn:externals wc/dir

echo "### Update working copy to get rid of file external..."
${SVN} up wc

echo "### Status should NOT contain external entry..."
${SVN} st -v wc
Received on 2010-01-20 21:43:25 CET