Fix to_dense_adj with empty edge_index

[rusty1s]

Fixes #5475

[codecov]

Codecov Report

Merging #5476 (b844c09) into master (707d26d) will decrease coverage by 1.97%.
The diff coverage is 75.00%.

@@            Coverage Diff             @@
##           master    #5476      +/-   ##
==========================================
- Coverage   85.35%   83.38%   -1.98%     
==========================================
  Files         350      350              
  Lines       19021    19021              
==========================================
- Hits        16235    15860     -375     
- Misses       2786     3161     +375     

Impacted Files	Coverage Δ
torch_geometric/data/hetero_data.py	95.50% <50.00%> (-0.47%)	⬇️
torch_geometric/utils/to_dense_adj.py	84.37% <100.00%> (+0.50%)	⬆️
torch_geometric/nn/models/dimenet_utils.py	0.00% <0.00%> (-75.52%)	⬇️
torch_geometric/nn/models/dimenet.py	14.51% <0.00%> (-53.00%)	⬇️
torch_geometric/profile/profile.py	37.89% <0.00%> (-26.32%)	⬇️
torch_geometric/nn/conv/utils/typing.py	81.25% <0.00%> (-17.50%)	⬇️
torch_geometric/nn/inits.py	67.85% <0.00%> (-7.15%)	⬇️
torch_geometric/nn/pool/asap.py	92.10% <0.00%> (-6.58%)	⬇️
torch_geometric/transforms/add_self_loops.py	94.44% <0.00%> (-5.56%)	⬇️
torch_geometric/nn/resolver.py	88.88% <0.00%> (-5.56%)	⬇️
... and 12 more

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[jiaruHithub]

Thanks a lot for this fix, Can I know how long time need to fix this problem? And how can I use fixed code of to_dense_adj if the error fixed, update my PyG or other ways?

[rusty1s]

You can install latest master via

pip install --upgrade git+https://github.com/pyg-team/pytorch_geometric.git