download, downloadunpacked: Disable shared feature by default since it is stil...

download, downloadunpacked: Disable shared feature by default since it is stil an experimental one. Enable it only if shared-part is defined.

slapos/recipe/download.py

@@ -53,12 +53,8 @@ class Recipe(object):
 
     destination = options.get('destination', None)
     if destination is None:
-      if shared:
+      if shared and buildout['buildout'].get('shared-part', None):
         shared_part = buildout['buildout'].get('shared-part', None)
-        if not shared_part:
-          raise ValueError(
-            " Set ${buildout:shared-part} for shared feature")
-
         shared = os.path.join(shared_part.strip().rstrip('/'), name)
         if not os.path.exists(shared):
           os.makedirs(shared)

slapos/recipe/downloadunpacked.py

@@ -50,11 +50,8 @@ class Recipe:
     self.destination = self.options.get('destination', None)
     self.shared = shared = is_true(options.get('shared', 'false').lower())
     if self.destination is None:
-      if shared:
+      if shared and buildout['buildout'].get('shared-part', None):
         shared_part = buildout['buildout'].get('shared-part', None)
-        if not shared_part:
-          raise ValueError(
-            " Set ${buildout:shared-part} for shared feature")
         top_location = options.get('top_location', '')
         shared = os.path.join(shared_part.strip().rstrip('/'), top_location, name)
         if not os.path.exists(shared):