gnt-group add: Fix diskparam fill

This was a pretty non-obvious bug. A cluster looks sane after
gnt-cluster init, however on a daemon restart the diskparameters had the
default filled in. The same applies to gnt-group add. This is due to the
nature that UpgradeConfig() from NodeGroups did just populate them with
defaults if something was set on it.

Signed-off-by: René Nussbaumer <rn@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

lib/cmdlib.py

@@ -13589,7 +13589,7 @@ class LUGroupAdd(LogicalUnit):
                               constants.DISK_DT_TYPES)
       self.new_diskparams = self.op.diskparams
     else:
-      self.new_diskparams = None
+      self.new_diskparams = {}
     if self.op.ipolicy:
       cluster = self.cfg.GetClusterInfo()

lib/objects.py

@@ -1496,7 +1496,8 @@ class NodeGroup(TaggableObject):
     if self.mtime is None:
       self.mtime = time.time()
 
-    self.diskparams = UpgradeDiskParams(self.diskparams)
+    if self.diskparams is None:
+      self.diskparams = {}
     if self.ipolicy is None:
       self.ipolicy = MakeEmptyIPolicy()