Fix ContentBundle bundle_id

Most content bundles use global_name as the ID-style thing, as suggested
on the OLPC wiki. bundle_class seems undocumented and hence is not
present in any of the content bundles I have here.

Change get_bundle_id() to fall back on the global_name if no bundle_class
is set. This fixes a complete sugar crash when installing the standard
content bundles (it tried to send a None value over dbus).

src/sugar/bundle/contentbundle.py

@@ -54,6 +54,7 @@ class ContentBundle(Bundle):
         self._library_version = None
         self._bundle_class = None
         self._activity_start = None
+        self._global_name = None
 
         info_file = self.get_file('library/library.info')
         if info_file is None:
@@ -126,6 +127,11 @@ class ContentBundle(Bundle):
             raise MalformedBundleException(
                 'Content bundle %s does not specify a category' % self._path)
 
+        if cp.has_option(section, 'global_name'):
+            self._global_name = cp.get(section, 'global_name')
+        else:
+            self._global_name = None
+
         if cp.has_option(section, 'category_icon'):
             self._category_icon = cp.get(section, 'category_icon')
         else:
@@ -151,6 +157,11 @@ class ContentBundle(Bundle):
         else:
             self._activity_start = 'index.html'
 
+        if self._bundle_class is None and self._global_name is None:
+            raise MalformedBundleException(
+                'Content bundle %s must specify either global_name or '
+                'bundle_class' % self._path)
+
     def get_name(self):
         return self._name
 
@@ -201,7 +212,10 @@ class ContentBundle(Bundle):
     # TODO treat ContentBundle in special way
     # needs rethinking while fixing ContentBundle support
     def get_bundle_id(self):
-        return self._bundle_class
+        if self._bundle_class is not None:
+            return self._bundle_class
+        else:
+            return self._global_name
 
     # TODO treat ContentBundle in special way
     # needs rethinking while fixing ContentBundle support