Add a regression test for the god node guard on the fallback

Two different classes that both fail header parsing and happen to
share a class name and a method name must not let a call resolve to
either one.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
(cherry picked from commit 9e26952d8b)

tests/test_cpp_objc_cross_file_calls.py

@@ -167,6 +167,48 @@ def test_cpp_qualified_call_resolves_to_a_qualified_only_definition(tmp_path: Pa
     assert ("useIt()", "calls", "AHelper::FindNearest()", "EXTRACTED") in calls
 
 
+def test_cpp_qualified_only_call_stays_ambiguous_across_two_classes(tmp_path: Path):
+    """The exactly-one-candidate guard still applies to the qualified-only
+    fallback: two DIFFERENT classes that both fail header parsing and both
+    happen to share a class name and a method name must not let a call
+    resolve to either one."""
+    base = tmp_path / "src"
+    header = (
+        "#pragma once\n"
+        '#include "a.generated.h"\n'
+        "UCLASS()\n"
+        "class AFoo : public AActor {\n"
+        "    GENERATED_BODY()\n"
+        "public:\n"
+        "    UFUNCTION()\n"
+        "    static AFoo* FindNearest(UWorld* W);\n"
+        "};\n"
+    )
+    body = (
+        '#include "a.h"\n'
+        "AFoo* AFoo::FindNearest(UWorld* W) { return nullptr; }\n"
+    )
+    _write(base / "a.h", header)
+    _write(base / "a.cpp", body)
+    _write(base / "sub" / "a.h", header)
+    _write(base / "sub" / "a.cpp", body)
+    _write(base / "caller.cpp", (
+        '#include "a.h"\n'
+        "void useIt(UWorld* W) {\n"
+        "    AFoo* h = AFoo::FindNearest(W);\n"
+        "    (void)h;\n"
+        "}\n"
+    ))
+    paths = sorted(base.glob("*")) + sorted((base / "sub").glob("*"))
+    result = extract(paths, cache_root=tmp_path / "cache")
+
+    calls = _call_edges(result)
+    assert not any(
+        rel == "calls" and src == "useIt()"
+        for src, rel, _, _ in calls
+    )
+
+
 def test_cpp_this_member_call_resolves_to_enclosing_class(tmp_path: Path):
     # `this->bar()` inside Foo::baz resolves to Foo::bar (the caller's own class) ->
     # EXTRACTED. Cross-file: the body lives in Foo.cpp, the decl in Foo.h.