Fix: Node editor "Group" panel displays for embedded node trees

Embedded node trees are not groups, since their inputs and outputs
are not exposed anywhere. So these panels should not be displayed.

release/scripts/startup/bl_ui/space_node.py

@@ -727,7 +727,20 @@ class NODE_UL_interface_sockets(bpy.types.UIList):
             layout.template_node_socket(color=color)
 
 
-class NodeTreeInterfacePanel:
+class NodeTreeInterfacePanel(Panel):
+
+    @classmethod
+    def poll(cls, context):
+        snode = context.space_data
+        if snode is None:
+            return False
+        tree = snode.edit_tree
+        if tree is None:
+            return False
+        if tree.is_embedded_data:
+            return False
+        return True
+
     def draw_socket_list(self, context, in_out, sockets_propname, active_socket_propname):
         layout = self.layout
 
@@ -804,32 +817,22 @@ class NodeTreeInterfacePanel:
             active_socket.draw(context, layout)
 
 
-class NODE_PT_node_tree_interface_inputs(NodeTreeInterfacePanel, Panel):
+class NODE_PT_node_tree_interface_inputs(NodeTreeInterfacePanel):
     bl_space_type = 'NODE_EDITOR'
     bl_region_type = 'UI'
     bl_category = "Group"
     bl_label = "Inputs"
 
-    @classmethod
-    def poll(cls, context):
-        snode = context.space_data
-        return snode.edit_tree is not None
-
     def draw(self, context):
         self.draw_socket_list(context, "IN", "inputs", "active_input")
 
 
-class NODE_PT_node_tree_interface_outputs(NodeTreeInterfacePanel, Panel):
+class NODE_PT_node_tree_interface_outputs(NodeTreeInterfacePanel):
     bl_space_type = 'NODE_EDITOR'
     bl_region_type = 'UI'
     bl_category = "Group"
     bl_label = "Outputs"
 
-    @classmethod
-    def poll(cls, context):
-        snode = context.space_data
-        return snode.edit_tree is not None
-
     def draw(self, context):
         self.draw_socket_list(context, "OUT", "outputs", "active_output")