These instructions assume that you have the Xcode Tools installed, and they use wget to grab the source.

# grab the source
wget http://subversion.tigris.org/tarballs/subversion-1.1.2.tar.gz


# stop anything that might be accessing the repository
sudo /usr/local/apache2/bin/apachectl stop


# expand the source archive
tar xzvf subversion-1.1.2.tar.gz 
cd subversion-1.1.2/


# remove old copies of libraries as per INSTALL
sudo rm -f /usr/local/lib/libsvn*
sudo rm -f /usr/local/lib/libapr*
sudo rm -f /usr/local/lib/libexpat*
sudo rm -f /usr/local/lib/libneon*


# build
sh ./autogen.sh
./configure
make
sudo make install


# enjoy the fruits of your labour
svn --version
sudo /usr/local/apache2/bin/apachectl start

One thing to note: the change log states that 1.1.2 "adds support for BerkeleyDB 4.3". The previous lack of support for 4.3 was something I stumbled across last time. Nevertheless, even if some support has been added under the hood, the build process failed if I tried using the following configure option:

./configure --with-berkeley-db=/usr/local/BerkeleyDB.4.3

As such, I am not really sure what the note about 4.3 in the changelog means. The Subversion issue tracker has an issue about this, but it's currently marked as being slated for version 1.3, which is still a long way off.