fix(tools): fail closed on missing managed report for accepted programs (fixes #3251)

tools/corpus_harness.py

@@ -176,7 +176,14 @@ def run_checker(bin_path, hy_path, report_managed=False):
         # Parse failures have no managed report. A report that is present
         # must carry the usize counters emitted by hy_diag::ManagedReport;
         # silently defaulting malformed counters to zero hides audit drift.
-        if managed is not None:
+        # An accepted program must carry a managed report when requested.
+        if managed is None:
+            if verdict == "accept":
+                raise RuntimeError(
+                    f"checker managed report missing for {hy_path}: "
+                    "accepted program omitted summary.managed"
+                )
+        else:
             if not isinstance(managed, dict):
                 raise RuntimeError(f"checker managed report invalid for {hy_path}: expected an object")
             for field in ("managed_blocks", "sites_via_managed", "total_sites"):

tools/test_corpus_harness.py

@@ -305,6 +305,20 @@ def test_absent_or_null_report_keeps_parser_reject_contract(self):
                 self.assertIn("verdict agreement: 1/1", run.stdout)
                 self.assertNotIn("Traceback", run.stderr)
 
+    def test_missing_or_null_report_on_accept_fails_closed(self):
+        # Issue #3251: an accepted response lacking summary.managed must fail closed
+        # instead of silently aggregating missing data as zero counters.
+        self.assert_invalid_report(None)
+        payload = {
+            "summary": {"verdict": "accept", "errors": 0, "warnings": 0},
+            "diagnostics": [],
+        }
+        run = self.run_cases([("ACCEPT", payload, 0)])
+        self.assertEqual(run.returncode, 1, run.stdout + run.stderr)
+        self.assertIn("harness-error", run.stdout)
+        self.assertIn("verdict agreement: 0/1", run.stdout)
+        self.assertNotIn("Traceback", run.stderr)
+
     def test_report_validation_only_applies_with_report_flag(self):
         for managed in (False, 0, "", [], [1], "x",
                         {"managed_blocks": -1, "sites_via_managed": 5,