_shove_recover_room clobbered a net's _Accepted with a fresh one whose
wire_owners held only the just-recovered wire, while its wires list (the
shared result.wires[net_no]) already held earlier committed connections.
That left wire_owners shorter than the parallel wires list, so a later
net's shove either removed the wrong wire's copper from the search tree
(a silent different-net short: copper stayed in the emitted SES but
vanished from the tree, and has_violation falsely certified it clean) or
raised IndexError and aborted the whole route.
Reuse the net's existing _Accepted on recovery so wire_owners stays
parallel to wires. Fixes both the silent DRC violation and the crash
sibling without touching the DRC-clean or determinism invariants.
Also correct the overstated "density win" framing of the shove_channel
fixture: its plain-routing net drop is an artifact of greedy net order,
not a density limit (the same board routes both nets with zero shoves
under a reorder or with the cosmetic seals removed). Reframed the test
and docstring; the genuine sub-cell win remains the wide_door occupancy
packing (shoves == 0).
Regression tests assert the invariant against the emitted output
directly (reconstructed copper tiles), not just the tree that the bug
fooled, plus determinism, no-crash, and the ordering-artifact bound.
Ryan Malloy
9cf2392c4b