test-extension: fix disabled extension tests for run-tests.py --local

One test that requires inserting a broken extension into hgext does this
by modifying PYTHONPATH. This doesn't work when run with --local because
the 'hg' script being used is in the same directory as the local hgext.

Instead of modifying PYTHONPATH, a secondary extension is enabled using
--config that inserts the dummy hgext at the beginning of sys.path,
before the script's path.

tests/test-extension

@@ -1,179 +1,180 b''
 #!/bin/sh
 # Test basic extension support
 
 "$TESTDIR/hghave" no-outer-repo || exit 80
 
 cat > foobar.py <<EOF
 import os
 from mercurial import commands
 
 def uisetup(ui):
     ui.write("uisetup called\\n")
 
 def reposetup(ui, repo):
     ui.write("reposetup called for %s\\n" % os.path.basename(repo.root))
     ui.write("ui %s= repo.ui\\n" % (ui == repo.ui and "=" or "!"))
 
 def foo(ui, *args, **kwargs):
     ui.write("Foo\\n")
 
 def bar(ui, *args, **kwargs):
     ui.write("Bar\\n")
 
 cmdtable = {
     "foo": (foo, [], "hg foo"),
     "bar": (bar, [], "hg bar"),
 }
 
 commands.norepo += ' bar'
 EOF
 abspath=`pwd`/foobar.py
 
 mkdir barfoo
 cp foobar.py barfoo/__init__.py
 barfoopath=`pwd`/barfoo
 
 hg init a
 cd a
 echo foo > file
 hg add file
 hg commit -m 'add file'
 
 echo '[extensions]' >> $HGRCPATH
 echo "foobar = $abspath" >> $HGRCPATH
 hg foo
 
 cd ..
 hg clone a b
 
 hg bar
 echo 'foobar = !' >> $HGRCPATH
 
 echo '% module/__init__.py-style'
 echo "barfoo = $barfoopath" >> $HGRCPATH
 cd a
 hg foo
 echo 'barfoo = !' >> $HGRCPATH
 
 # check that extensions are loaded in phases
 cat > foo.py <<EOF
 import os
 name = os.path.basename(__file__).rsplit('.', 1)[0]
 print "1) %s imported" % name
 def uisetup(ui):
     print "2) %s uisetup" % name
 def extsetup():
     print "3) %s extsetup" % name
 def reposetup(ui, repo):
     print "4) %s reposetup" % name
 EOF
 
 cp foo.py bar.py
 echo 'foo = foo.py' >> $HGRCPATH
 echo 'bar = bar.py' >> $HGRCPATH
 
 # command with no output, we just want to see the extensions loaded
 hg paths
 
 # check hgweb's load order
 echo '% hgweb.cgi'
 cat > hgweb.cgi <<EOF
 #!/usr/bin/env python
 from mercurial import demandimport; demandimport.enable()
 from mercurial.hgweb import hgweb
 from mercurial.hgweb import wsgicgi
 
 application = hgweb('.', 'test repo')
 wsgicgi.launch(application)
 EOF
 SCRIPT_NAME='/' SERVER_PORT='80' SERVER_NAME='localhost' python hgweb.cgi \
     | grep '^[0-9]) ' # ignores HTML output
 
 echo 'foo = !' >> $HGRCPATH
 echo 'bar = !' >> $HGRCPATH
 
 cd ..
 cat > empty.py <<EOF
 '''empty cmdtable
 '''
 cmdtable = {}
 EOF
 emptypath=`pwd`/empty.py
 echo "empty = $emptypath" >> $HGRCPATH
 hg help empty
 echo 'empty = !' >> $HGRCPATH
 
 cat > debugextension.py <<EOF
 '''only debugcommands
 '''
 def debugfoobar(ui, repo, *args, **opts):
     "yet another debug command"
     pass
 
 def foo(ui, repo, *args, **opts):
     """yet another foo command
 
     This command has been DEPRECATED since forever.
     """
     pass
 
 cmdtable = {
     "debugfoobar": (debugfoobar, (), "hg debugfoobar"),
     "foo": (foo, (), "hg foo")
 }
 EOF
 debugpath=`pwd`/debugextension.py
 echo "debugextension = $debugpath" >> $HGRCPATH
 echo "% hg help"
 hg help debugextension
 echo "% hg help --verbose"
 hg --verbose help debugextension
 echo "% hg help --debug"
 hg --debug help debugextension
 echo 'debugextension = !' >> $HGRCPATH
 
 echo % issue811
 debugpath=`pwd`/debugissue811.py
 cat > debugissue811.py <<EOF
 '''show all loaded extensions
 '''
 from mercurial import extensions, commands
 
 def debugextensions(ui):
     "yet another debug command"
     ui.write("%s\n" % '\n'.join([x for x, y in extensions.extensions()]))
 
 cmdtable = {"debugextensions": (debugextensions, (), "hg debugextensions")}
 commands.norepo += " debugextensions"
 EOF
 echo "debugissue811 = $debugpath" >> $HGRCPATH
 echo "mq=" >> $HGRCPATH
 echo "hgext.mq=" >> $HGRCPATH
 echo "hgext/mq=" >> $HGRCPATH
 
 echo % show extensions
 hg debugextensions
 
 echo '% disabled extension commands'
 HGRCPATH=
 hg help email
 hg qdel
 hg churn
 echo '% disabled extensions'
 hg help churn
 hg help patchbomb
 echo '% broken disabled extension and command'
 mkdir hgext
 echo > hgext/__init__.py
 cat > hgext/broken.py <<EOF
 "broken extension'
 EOF
-TMPPYTHONPATH="$PYTHONPATH"
-PYTHONPATH="`pwd`:$PYTHONPATH"
-export PYTHONPATH
-hg help broken
-hg help foo > /dev/null
-PYTHONPATH="$TMPPYTHONPATH"
-export PYTHONPATH
+cat > path.py <<EOF
+import os, sys
+sys.path.insert(0, os.environ['HGEXTPATH'])
+EOF
+HGEXTPATH=`pwd`
+export HGEXTPATH
+hg --config extensions.path=./path.py help broken
+hg --config extensions.path=./path.py help foo > /dev/null
 
 exit 0