Dictionary iteration error when dealing with subgraphs

[herronelou]

Hello,

I found an issue with expanding graphs:

NodeGraphQt/NodeGraphQt/base/graph.py

Line 2958 in a8fa9b3

for grp_node_id, grp_sub_graph in self.sub_graphs.items():

At this line 👆 you iterate though the items of an internal dict.
A few lines lower, within the iteration there is this call: 👇

NodeGraphQt/NodeGraphQt/base/graph.py

Line 2962 in a8fa9b3

self.collapse_group_node(grp_node)

However, the function called from there 👆 is modifying the same internal dict 👇

NodeGraphQt/NodeGraphQt/base/graph.py

Line 2997 in a8fa9b3

sub_graph = self.sub_graphs.pop(node.id, None)

As a result, it raises RuntimeError: dictionary changed size during iteration

This is likely a result of a Python2 to Python3 change, where the result of dict.items() changed from a list to an iterator.

[herronelou]

Confirmed that if if I patch line 2958 with this:

-        for grp_node_id, grp_sub_graph in self.sub_graphs.items():
+        for grp_node_id, grp_sub_graph in list(self.sub_graphs.items()):

It seems to make things work again by mimicking the results of Python 2. That's a lazy fix, but it works.