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

# Makefile for testing hgsubversion

PYTHON=python

.PHONY: all check check-demandimport check-subvertpy check-swig

all:
	@echo "Use the following commands to build and install hgsubversion:"
	@echo
	@echo "$$ cd $(PWD)"
	@echo "$$ $(PYTHON) ./setup.py install"
	@echo
	@exit 1

check: check-demandimport check-subvertpy check-swig

check-demandimport:
	# verify that hgsubversion loads properly without bindings, but fails
	# when actually used
	! LC_ALL=C HGSUBVERSION_BINDINGS=none HGRCPATH=/dev/null \
	  hg --config extensions.hgsubversion=./hgsubversion \
	  version 2>&1 \
	  | egrep '(^abort:|failed to import extension)'
	LC_ALL=C HGSUBVERSION_BINDINGS=none HGRCPATH=/dev/null \
	  hg --config extensions.hgsubversion=./hgsubversion \
	  version --svn 2>&1 \
	  | egrep '(^abort:|failed to import extension)'

check-subvertpy:
	$(PYTHON) tests/run.py --all --bindings=subvertpy

check-swig:
	$(PYTHON) tests/run.py --all --bindings=swig