Panic from ancestors and descendants

[barakatzir]

Information

• rustworkx version: currently on main (commit f2f45425c70b49d89aa5527271a34f64fb114f1d)
• Python version: 3.12
• Rust version: ...
• Operating system: ubuntu

What is the current behavior?

When calling rustworkx.ancestors or rustworkx.descendants with index not in graph a PanicExpection is raised

I haven't checked, but I suspect that this bug is also present in rustworkx-core.

What is the expected behavior?

I expected either an IndexError or an empty set (similar to say predecessor_indices method that return an empty NodeIndices in similar situation).

Steps to reproduce the problem

# t.py

import rustworkx as rx

graph = rx.PyDiGraph()
graph.extend_from_edge_list([(0, 1), (2, 1), (3, 1), (1, 4)])
rx.ancestors(graph, 10)

When run python t.py I get

thread '<unnamed>' panicked at /home/barak-katzir/.cargo/registry/src/index.crates.io-6f17d22bba15001f/fixedbitset-0.5.7/src/lib.rs:486:9:
put at index 10 exceeds fixedbitset size 5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Traceback (most recent call last):
  File "/home/barak-katzir/dev/rustworkx-check/t.py", line 7, in <module>
    rx.descendants(graph, 10)
pyo3_runtime.PanicException: put at index 10 exceeds fixedbitset size 5

and similarly for rustworkx.descendants.

[IvanIsCoding]

I will send a patch tomorrow, I suspect we are missing an index check as you mentioned