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 mergeexternals.svndump
#

mkdir temp
cd temp

mkdir project-orig
cd project-orig
mkdir trunk
mkdir branches
cd ..

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

svn co $svnurl project
cd project/trunk
mkdir d1
echo a > d1/a
mkdir d2
echo b > d2/b
mkdir -p common/ext
echo c > common/ext/c
svn add d1 d2 common
svn ci -m addfiles
svn up
svn propset svn:externals '^/trunk/common/ext ext' d1
svn propset svn:externals '^/trunk/common/ext ext' d2
svn ci -m addexternals
cd ..
svn up
svn cp trunk branches/branch
cd branches
svn ci -m addbranch
cd branch
mkdir d3
echo d > d3/d
svn add d3
svn propset svn:externals '^/trunk/common/ext ext3' d3
svn ci -m touchbranch
cd ../../trunk
svn merge '^/branches/branch'
svn up
svn ci -m 'merge'
cd ../..

svnadmin dump testrepo > ../mergeexternals.svndump