pushmod: prepend "link " to base text for links http://svn.apache.org/viewvc?view=revision&revision=1223036 exposes what is arguably a bug in hgsubversion push code. Specifically, when we are receiving text from the server in an editor, we prepend a "link " to the text of symlinks when opening a file and strip it when closing a file. We don't, however, prepend "link " to the base we use when sending text changes to the server. This was working before because prior to that revision, the first thing subversion did was to check whether the entirety of the before text or the entirety of the after text was less than 64 bytes. In that case, it just sent the entirety of the after text as a single insert operation. I'd expect most, but not all symlinks to fit under the 64 byte limit, including the leading "link " text on the subversion end. After the change, the first thing subversion does is check for a leading match that is more than 4 bytes long, or that is the full length of the after text. In this case, it sends a copy operation for the leading match, and then goes into the if < 64 bytes remaining send the whole thing behavior. It also looks for trailing matches of more than 4 bytes even in the <64 byte case, but that's not what breaks the tests. Incidentally, changing the destination of long symlinks was broken even before this subversion change. This diff includes test additions that cover that breakage.

#!/bin/sh
#
# Generate symlinks.svndump
#

mkdir temp
cd temp

mkdir project-orig
cd project-orig
mkdir trunk
mkdir branches
cd ..

svnadmin create testrepo
svnurl=file://`pwd`/testrepo
svn import project-orig $svnurl -m "init project"

svn co $svnurl project
cd project/trunk
echo a > a
ln -s a linka
ln -s a linka2
mkdir d
ln -s a d/linka
svn add a linka linka2 d
svn ci -m "add symlinks"
# Move symlinks
svn mv linka linkaa
svn mv d d2
svn commit -m "moving symlinks"
# Update symlinks (test "link " prefix vs applydelta)
echo b > b
rm linkaa
ln -s b linkaa
rm d2/linka
ln -s b d2/linka
svn ci -m "update symlinks"
# Replace a symlink with a regular file
rm linkaa
echo data > linkaa
svn propdel svn:special linkaa
# Replace another symlink with a regular file in another way
# It should mark linka2 as R(eplaced)
svn rm linka2
echo data2 > linka2
svn add linka2
svn propdel svn:special linka2
svn rm d2/linka
svn ci -m "undo link"
cd ../..

svnadmin dump testrepo > ../symlinks.svndump