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
#
# Generate revert.svndump
#

rm -rf temp
mkdir temp
cd temp
mkdir -p import/trunk/dir
cd import/trunk
echo a > a
echo b > dir/b
cd ../..

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

svn co $svnurl project
cd project
echo a >> trunk/a
echo b >> trunk/dir/b
svn ci -m changefiles
svn up
# Test directory revert
svn rm trunk
svn cp $svnurl/trunk@1 trunk
svn st
svn ci -m revert
svn up
# Test file revert
svn rm trunk/a
svn rm trunk/dir/b
svn cp $svnurl/trunk/a@2 trunk/a
svn cp $svnurl/trunk/dir/b@2 trunk/dir/b
svn ci -m revert2
cd ..

svnadmin dump testrepo > ../revert.svndump