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
#
# Generate copies.svndump
#

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

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

svn co $svnurl project
cd project
svn cp trunk/dir trunk/dir2
echo b >> trunk/dir2/a
svn ci -m 'copy/edit trunk/dir/a'
svn up
svn cp trunk/dir2 trunk/dir3
svn ci -m 'copy dir2 to dir3'
svn rm trunk/dir3/a
svn cp trunk/dir2/a trunk/dir3/a
svn ci -m 'copy and remove'
cd ..

svnadmin dump testrepo > ../copies.svndump