util: add visitor pattern for scrubbing json These functions are for future patches that will add safer serialization via json. '_convert' is a visitor pattern that will be used for lists, dictionaries, and strings for helping convert None to the empty string since json forbids 'null' as a key for a dictionary. None -> '' is a safe mapping because this is for the 'branch_info' variable which already maps the empty string to None. Note, also, that json is chosen instead of, say, csv because json has a concept of 'null' and will better handle utf8 strings (which subversion supports). Important: this changes the requirement of hgsubversion to python 2.6+.

#!/bin/sh
mkdir temp || exit 1
cd temp
svnadmin create repo
svn co file://`pwd`/repo wc
pushd wc
mkdir -p project/trunk
svn add project
svn ci -m 'trunk'
cd project/trunk
echo a > a
mkdir narf
svn add a narf
svn ci -m 'file and empty dir'
popd
svnadmin dump repo > ../empty_dir_in_trunk_not_repo_root.svndump
echo 'dump in empty_dir_in_trunk_not_repo_root.svndump'
echo 'you can probably delete temp now'