Fixed environment variable leaking between parts.

See http://github.com/hexagonit/hexagonit.recipe.cmmi/issues#issue/1

CHANGES.txt

@@ -12,6 +12,10 @@ Change History
    successful or not. Thanks to Jonathan Ballet for the report and preliminary
    patch. [dokai]
 
+ - Fixed http://github.com/hexagonit/hexagonit.recipe.cmmi/issues#issue/1
+   Environment variables defined in one part will no longer leak to other
+   subsequent parts. [dokai]
+
 1.3.0 (2009-09-20)
 ==================
 

hexagonit/recipe/cmmi/__init__.py

@@ -34,6 +34,8 @@ class Recipe(object):
             options['compile-directory'] = options['path']
 
         self.environ = {}
+        self.original_environment = os.environ.copy()
+
         environment_section = self.options.get('environment-section', '').strip()
         if environment_section and environment_section in buildout:
             # Use environment variables from the designated config section.
@@ -48,6 +50,14 @@ class Recipe(object):
         for key in self.environ:
             self.environ[key] = self.environ[key] % os.environ
 
+    def restore_environment(self):
+        """Restores the original os.environ environment in case the recipe
+        made changes to it.
+        """
+        if self.environ:
+            os.environ.clear()
+            os.environ.update(self.original_environment)
+
     def update(self):
         pass
 
@@ -167,6 +177,7 @@ class Recipe(object):
                           'you can inspect what went wrong' % os.getcwd())
                 raise
         finally:
+            self.restore_environment()
             os.chdir(current_dir)
 
         if self.options['url']:

hexagonit/recipe/cmmi/tests.py

@@ -142,6 +142,29 @@ class NonInformativeTests(unittest.TestCase):
             except:
                 pass
 
+    def test_environment_restored_after_building_a_part(self):
+        # Make sure the test variables do not exist beforehand
+        self.failIf('HRC_FOO' in os.environ)
+        self.failIf('HRC_BAR' in os.environ)
+        # Place a sentinel value to make sure the original environment is
+        # maintained
+        os.environ['HRC_SENTINEL'] = 'sentinel'
+        self.assertEquals(os.environ.get('HRC_SENTINEL'), 'sentinel')
+
+        recipe = self.make_recipe({}, 'test', {
+            'url' : 'file://%s/testdata/package-0.0.0.tar.gz' % os.path.dirname(__file__),
+            'environment' : 'HRC_FOO=bar\nHRC_BAR=foo'})
+        os.chdir(self.dir)
+        recipe.install()
+
+        # Make sure the test variables are not kept in the environment after
+        # the part has been built.
+        self.failIf('HRC_FOO' in os.environ)
+        self.failIf('HRC_BAR' in os.environ)
+        # Make sure the sentinel value is still in the environment
+        self.assertEquals(os.environ.get('HRC_SENTINEL'), 'sentinel')
+
+
 def test_suite():
     suite = unittest.TestSuite((
             doctest.DocFileSuite(