Treenode back-end: make node insertion slighlty more robust

It seems to happen in very rare cases that a passed in radius or
confidence is NaN. Handling these situations more gracefully is use ful
to mitigate this behavior. It should still be checked why such
situations happen, but they shouldn't prevent node creation.

django/applications/catmaid/control/treenode.py

@@ -279,9 +279,11 @@ def insert_new_treenode(parent_id=None, skeleton_id=None):
         new_treenode.location_x = float(x)
         new_treenode.location_y = float(y)
         new_treenode.location_z = float(z)
-        new_treenode.radius = int(radius)
+        new_radius = int(radius if (radius and not math.isnan(radius)) else 0)
+        new_treenode.radius = new_radius
         new_treenode.skeleton_id = skeleton_id
-        new_treenode.confidence = int(confidence)
+        new_confidence = int(confidence if not math.isnan(confidence) and (confidence or confidence is 0) else 5)
+        new_treenode.confidence = new_confidence
         if parent_id:
             new_treenode.parent_id = parent_id
         new_treenode.save()