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

RSVN="`pwd`/rsvn.py"
export PATH=/bin:/usr/bin
mkdir temp
cd temp

svnadmin create repo
svn co file://`pwd`/repo wc

cd wc
mkdir trunk branches
cd trunk
for a in alpha beta gamma ; do
    echo $a > $a
done
cd ..
svn add *
svn ci -m 'initial'

svn up
svn cp trunk branches/test
svn ci -m 'branch'

svn up
echo foo >> branches/test/alpha
svn ci -m 'Mod.'

cd ..
echo rdelete trunk > tmp
echo rcopy branches/test trunk >> tmp
python $RSVN --message=blah --username=evil `pwd`/repo < tmp

svnadmin dump repo > ../replace_trunk_with_branch.svndump