Avoid auto-import of bundle helpers (#4527)

The new bundle helpers were being auto-loaded with sugar3.bundle due
to their placement in __init__.py. This was causing Gi to be imported,
breaking GTK2 activity launches.

Move the helpers to a dedicated module.

src/sugar3/bundle/Makefile.am

@@ -4,4 +4,5 @@ sugar_PYTHON =				\
 	bundle.py			\
 	activitybundle.py		\
 	bundleversion.py		\
-	contentbundle.py
+	contentbundle.py		\
+	helpers.py

src/sugar3/bundle/__init__.py

@@ -14,37 +14,3 @@
 # License along with this library; if not, write to the
 # Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 # Boston, MA 02111-1307, USA.
-
-import os
-
-from gi.repository import Gio
-
-from sugar3.bundle.activitybundle import ActivityBundle
-from sugar3.bundle.contentbundle import ContentBundle
-
-
-def bundle_from_archive(path, mime_type=None):
-    """
-    Return an appropriate Bundle object for a given file path.
-    The bundle type is identified by mime_type, which is guessed if not
-    provided.
-    """
-    if mime_type is None:
-        mime_type, certainty = Gio.content_type_guess(path, data=None)
-    if mime_type == ActivityBundle.MIME_TYPE:
-        return ActivityBundle(path)
-    elif mime_type == ContentBundle.MIME_TYPE:
-        return ContentBundle(path)
-    return None
-
-
-def bundle_from_dir(path):
-    """
-    Return an appropriate Bundle object for a given directory containing
-    an unzipped bundle.
-    """
-    if os.path.exists(os.path.join(path, 'activity', 'activity.info')):
-        return ActivityBundle(path)
-    elif os.path.exists(os.path.join(path, 'library', 'library.info')):
-        return ContentBundle(path)
-    return None

src/sugar3/bundle/helpers.py

@@ -0,0 +1,50 @@
+# Copyright (C) 2013 One Laptop per Child
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the
+# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+# Boston, MA 02111-1307, USA.
+
+import os
+
+from gi.repository import Gio
+
+from sugar3.bundle.activitybundle import ActivityBundle
+from sugar3.bundle.contentbundle import ContentBundle
+
+
+def bundle_from_archive(path, mime_type=None):
+    """
+    Return an appropriate Bundle object for a given file path.
+    The bundle type is identified by mime_type, which is guessed if not
+    provided.
+    """
+    if mime_type is None:
+        mime_type, certainty = Gio.content_type_guess(path, data=None)
+    if mime_type == ActivityBundle.MIME_TYPE:
+        return ActivityBundle(path)
+    elif mime_type == ContentBundle.MIME_TYPE:
+        return ContentBundle(path)
+    return None
+
+
+def bundle_from_dir(path):
+    """
+    Return an appropriate Bundle object for a given directory containing
+    an unzipped bundle.
+    """
+    if os.path.exists(os.path.join(path, 'activity', 'activity.info')):
+        return ActivityBundle(path)
+    elif os.path.exists(os.path.join(path, 'library', 'library.info')):
+        return ContentBundle(path)
+    return None

tests/test_bundle.py

@@ -18,7 +18,7 @@ import os
 import unittest
 import subprocess
 
-from sugar3.bundle import bundle_from_dir, bundle_from_archive
+from sugar3.bundle.helpers import bundle_from_dir, bundle_from_archive
 from sugar3.bundle.activitybundle import ActivityBundle
 from sugar3.bundle.contentbundle import ContentBundle