layouts: fix crash when importing hgsubversion itself (issue #402) Mercurial extensions are a bit weird: they aren't normally in sys.path, so you can't assume that "import hgsubversion" works. Luckily, Mercurial sneaks a little treat into sys.modules so that "import hgext_hgsubversion" does work. In fact, to get things working *as a Mercurial extension*, all that's needed is that trivial change to two import lines, in layouts/detect.py and layouts/standard.py. Unfortunately, hgsubversion is also imported as a Python module, in its own test suite. In that context, there is no "hgext_" trick -- unless we do it in ourselves, which I've done in TestBase.setUp(). That would work fine ... except that test_util imports from hgsubversion, which ends up importing hgsubversion.layouts.{detect,standard}, which want the "hgext_" trick to work. But it hasn't been done yet when we're still importing; it doesn't happen until setUp() runs. So make those two imports happen late, in the functions that need them. Incidentally, this is only necessary to support Mercurial <= 2.7. Mercurial got a bit smarter in 2.8: http://selenic.com/repo/hg/rev/621a26eb3a99

#!/bin/sh
#
# Create emptyrepo2.svndump
#
# The generated repository contains a sequence of empty revisions
# created with a combination of svnsync and filtering

mkdir temp
cd temp

mkdir project-orig
cd project-orig
mkdir -p sub/trunk other
echo a > other/a
cd ..

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

svn co $svnurl project
cd project
echo a >> other/a
svn ci -m othera
echo a >> other/a
svn ci -m othera2
echo b > sub/trunk/a
svn add sub/trunk/a
svn ci -m adda
cd ..

svnadmin create testrepo2
cat > testrepo2/hooks/pre-revprop-change <<EOF
#!/bin/sh
exit 0
EOF
chmod +x testrepo2/hooks/pre-revprop-change

svnurl2=file://`pwd`/testrepo2
svnsync init --username svnsync $svnurl2 $svnurl/sub
svnsync sync $svnurl2

svnadmin dump testrepo2 > ../emptyrepo2.svndump