diamond hunt: godot-0009/0010 + meson-0002 + typeorm-0004/0005 + ts-0003; count 629→635

New diamond recursion defects (O(2^D) → O(N)):
- godot-0009: Font::_is_cyclic no visited set — CJK fallback diamond, 2648x at F=4,D=8
- godot-0010: Font::_update_rids_fb no visited set — duplicate RIDs + O(N^2) hot path
- meson-0002: get_internal_static_libraries_recurse link_whole guard missing — 132x at D=10
- typescript-0003: hasBaseType inner check() no visited set — 1024x at D=10; hot on instanceof

New O(N²) defects:
- typeorm-0004: SubjectTopologicalSorter Array.indexOf dedup — 200x at N=400
- typeorm-0005: DepGraph.createDFS result.indexOf + addDependency edge dedup — 300x at N=600

CLEAN confirmed (diamond recursion sweep): bazel, cargo, cmake, composer, dgl, diesel,
doctrine-orm, efcore, helm, mybatis, networkx-deeper, ninja, npm-arborist, peewee, pip,
rubygems, seaorm, sqlalchemy, swift

UNDF: 571→578 assigned; MOAD count: 629→635

defects/cargo/patch/cargo-diamond-recursion-CLEAN.md

@@ -0,0 +1,20 @@
+## Diamond Recursion Scan — CLEAN
+
+**Scan date:** 2026-03-29
+**Pattern:** Recursive cycle/dependency check without visited set (CWE-407 diamond recursion, O(2^D))
+
+### Files examined
+
+- `src/cargo/core/resolver/mod.rs` — `check_cycles`, `visit`
+- `src/cargo/ops/tree/graph.rs` — `from_reachable`
+- `src/cargo/ops/cargo_compile/mod.rs` — `visit` function in dependency compilation
+
+### Findings
+
+**check_cycles / visit:** Uses two `HashSet<PackageId>` accumulators: `visited` (current DFS path, cleared on backtrack) and `checked` (globally confirmed-clean nodes). Properly prevents diamond re-traversal. O(V+E). CLEAN.
+
+**cargo_compile visit:** Uses `visited: &mut HashSet<Unit>` passed to all recursive calls. O(V+E). CLEAN.
+
+Note: `cargo-0001` and `cargo-0002` cover pre-existing CWE-407 defects in print_stack and add_edge operations.
+
+### Verdict: CLEAN — no diamond recursion CWE-407 found