[Fix, Test] (workflows, scripts/ci): make the three CI negative controls assert their own failure reason instead of accepting any non-zero ctest exit, count the arming baseline by PASSED rather than by not-skipped, and put both control bodies in files a smoke test can drive against a stubbed ctest

scripts/ci/junit_tally.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+"""Tally a ctest --output-junit file as "passed failed skipped".
+
+Split out of .github/workflows/test.yml's negative-control step so that the workflow, the local
+gate and the control smoke test all count a run the same way.
+
+WHY THIS EXISTS AT ALL (ID-46 finding 8, second half). The counter this replaces lived inline in
+the workflow and counted a case as having "run" when it was merely not <skipped/>:
+
+    if case.find('skipped') is None and case.get('status') not in ('notrun', 'disabled'):
+        ran += 1
+
+so a case that RAN AND FAILED armed the negative controls below it. Combined with the `|| true`
+that hid the baseline's exit code, a lane in which every split entry was already red reported
+itself armed, and a control that turns an already-red entry red then "passed". Passed, failed and
+skipped are three different answers and the caller needs all three.
+"""
+
+import sys
+import xml.etree.ElementTree as ET
+
+
+def tally(path):
+    passed = failed = skipped = 0
+    for case in ET.parse(path).getroot().iter('testcase'):
+        if case.find('failure') is not None or case.find('error') is not None:
+            failed += 1
+        elif case.find('skipped') is not None or case.get('status') in ('notrun', 'disabled'):
+            skipped += 1
+        else:
+            passed += 1
+    return passed, failed, skipped
+
+
+def main():
+    if len(sys.argv) != 2:
+        print("usage: junit_tally.py <junit.xml>", file=sys.stderr)
+        return 2
+    try:
+        passed, failed, skipped = tally(sys.argv[1])
+    except Exception as exc:  # a malformed file is not "zero of everything"
+        print(f"junit_tally: cannot parse {sys.argv[1]}: {exc}", file=sys.stderr)
+        return 1
+    print(f"{passed} {failed} {skipped}")
+    return 0
+
+
+if __name__ == '__main__':
+    raise SystemExit(main())