CommitTool: No need to set Predecessor if its the premier commit

product/ERP5/Tool/CommitTool.py

@@ -192,10 +192,12 @@ class CommitTool (BaseTool):
       commit_list = [l for l
                      in self.objectValues(portal_type='Business Commit')
                      if l != new_obj]
+
+      if commit_list:
         latest_commit = max(commit_list, key=(lambda x: x.getCreationDate()))
 
         if new_obj.getPortalType() == 'Business Commit':
-        # TODO: Add check for no latest_commit. Usable especially for 1st BM
+          # TODO: Add check for no latest_commit. Usable especially for 1st BC
           new_obj.setPredecessorValue(latest_commit)
         else:
           # If the new_obj is Business Snapshot, create a similar value for the