fix(guard,#15650): kernel drift exemption accepte l'en-tête C.4 suffixé (cas vécu #17220)

scripts/notebook_tools/check_kernel_drift.py

@@ -198,12 +198,21 @@ def body_has_derive_exemption(body):
     tolerates the unaccented 'derive' (covers authors who type the header
     without the accent, a common shortcut when reviewing on a non-French
     keyboard layout).
+
+    Fix v3 (suffix form, cas vecu #17220): also tolerate a trailing
+    parenthetical qualifier, e.g. '## Diagnostic derive (C.4)' -- the exact
+    form used in the PR body of #17220, whose exemption silently failed to
+    fire because
+    the strict end-of-line anchor rejected the '(C.4)' suffix (measured
+    firsthand 2026-09-21: kernel_diffs downgraded nowhere, guard red on a
+    3.13.7 -> 3.13.15 patch drift that the C.4 section was documenting).
     """
     if not body:
         return False
-    # Case-insensitive header, optional whitespace, optional accent on 'e'.
+    # Case-insensitive header, optional whitespace, optional accent on 'e',
+    # optional trailing parenthetical qualifier such as '(C.4)'.
     pattern = re.compile(
-        r"^##\s*Diagnostic\s*d[ée]rive\s*$",
+        r"^##\s*Diagnostic\s*d[ée]rive(?:\s*\([^)]*\))?\s*$",
         re.MULTILINE | re.IGNORECASE,
     )
     return bool(pattern.search(body))

scripts/notebook_tools/tests/test_check_kernel_drift_fixes.py

@@ -43,6 +43,29 @@ def test_body_empty_no_exemption():
     assert ckd.body_has_derive_exemption("") is False
 
 
+def test_body_derive_suffix_parenthetical_exempts():
+    """Suffix form '## Diagnostic derive (C.4)' exempts (cas vecu #17220).
+
+    The strict end-of-line anchor used to reject the parenthetical
+    qualifier, so a PR whose C.4 section was properly written but suffixed
+    with '(C.4)' silently lost the exemption.
+    """
+    body = "## Summary\nFix\n\n## Diagnostic derive (C.4)\nverdict CAUSE_FIXED\n"
+    assert ckd.body_has_derive_exemption(body) is True
+
+
+def test_body_derive_suffix_parenthetical_accented_exempts():
+    """Accented suffix form '## Diagnostic dérive (C.4)' exempts."""
+    body = "## Summary\nFix\n\n## Diagnostic dérive (C.4)\nverdict CAUSE_FIXED\n"
+    assert ckd.body_has_derive_exemption(body) is True
+
+
+def test_body_derive_trailing_garbage_no_exemption():
+    """Arbitrary trailing text (not a single parenthetical) stays rejected."""
+    body = "## Summary\nFix\n\n## Diagnostic derive and other notes\n"
+    assert ckd.body_has_derive_exemption(body) is False
+
+
 # === Defect 5: float_signatures normalization ===
 
 def test_float_signatures_text_plain_list():