dgl.sampling.sample_neighbors return zero or less edges when setting excluded_edges

[xansar]

🐛 Bug

when setting excluded_edges, this function will return a graph with edges less than fanout.

To Reproduce

Steps to reproduce the behavior:

1. create a graph u1 = torch.tensor([0, 0, 1, 1, 2, 3]) u2 = torch.tensor([1, 2, 3, 4, 5, 4]) g = dgl.graph((u1, u2), num_nodes=6) g.all_edges(form='all')
2. sample with out excluded_edges sg = dgl.sampling.sample_neighbors(g, nodes=[1], fanout=2, replace=True, edge_dir='out') sg.edges(order='eid'), sg.edata[dgl.EID], sg.num_edges() ((tensor([1, 1]), tensor([4, 4])), tensor([3, 3]), 2)
3. sample with excluded_edges A bug will occur, and sometimes this function will return a graph without edges: sg = dgl.sampling.sample_neighbors(g, nodes=[1], fanout=2, replace=True, edge_dir='out', exclude_edges=[3]) sg.edges(order='eid'), sg.edata[dgl.EID], sg.num_edges() ((tensor([], dtype=torch.int64), tensor([], dtype=torch.int64)), sometimes with one edge: ((tensor([1]), tensor([3])), tensor([2]), 1)

Expected behavior

fix this bug

Environment

• DGL Version (e.g., 1.0): 0.9.1
• Backend Library & Version (e.g., PyTorch 0.4.1, MXNet/Gluon 1.3): PyTorch 1.12.1
• OS (e.g., Linux): Windows
• How you installed DGL (conda, pip, source): pip
• Python version: 3.8
• CUDA/cuDNN version (if applicable): cuda11.6
• GPU models and configuration (e.g. V100): Nvidia RTX 2060

Additional context

[mufeili]

Could you take a look? @BarclayII

[BarclayII]

I should have fixed the bug in #4732 . Could you try the nightly version?

[github-actions[bot]]

This issue has been automatically marked as stale due to lack of activity. It will be closed if no further activity occurs. Thank you