fix(#6056): extend sidebar title-field redaction to /api/sessions/search (Codex class-fix)

Codex re-gate found the same derived-title leak on the sibling /api/sessions/search
endpoint (3 branches redacted only 'title'). Extract _redact_sidebar_title_fields()
shared helper, apply it in both _sidebar_session_response_item and all 3 search
branches, read api_redact_enabled once per search response (mirrors #4662). +helper
test + source-guard that every search branch calls the redactor.

api/routes.py

@@ -9632,24 +9632,30 @@ def _sidebar_session_response_item(session: dict, *, redact_enabled: bool | None
     }
     if isinstance(item.get("title"), str):
         item["title"] = _redact_text(item["title"], _enabled=redact_enabled)
-    # display_title / _state_db_title can carry raw user-message-derived text
+    _redact_sidebar_title_fields(item, redact_enabled)
-    # (e.g. #6056 derives a delegated subagent's sidebar title from its first
-    # user message), so they must go through the SAME redaction as title — a
-    # credential-shaped value in a delegated goal would otherwise leak to the
-    # sidebar even with api_redact_enabled=True.
-    if isinstance(item.get("display_title"), str):
-        item["display_title"] = _redact_text(item["display_title"], _enabled=redact_enabled)
-    if isinstance(item.get("_state_db_title"), str):
-        item["_state_db_title"] = _redact_text(item["_state_db_title"], _enabled=redact_enabled)
-    # parent_title is a copied parent-session title that surfaces in the sidebar
-    # lineage collapse; redact it on the same path so a parent whose title was
-    # itself user-content-derived can't leak through the child row.
-    if isinstance(item.get("parent_title"), str):
-        item["parent_title"] = _redact_text(item["parent_title"], _enabled=redact_enabled)
     item["attention"] = _session_attention_summary(str(item.get("session_id") or ""))
     return item
 
 
+def _redact_sidebar_title_fields(item: dict, redact_enabled: bool | None = None) -> None:
+    """Redact every user-content-derived title field on a sidebar/search row in place.
+
+    `title` is redacted by the callers directly (they special-case it), but
+    `display_title`, `_state_db_title`, and `parent_title` can ALSO carry raw
+    user-message-derived text — e.g. #6056 derives a delegated subagent's
+    `display_title` from its first user message, and `parent_title` copies a
+    parent session's (possibly derived) title. Without this a credential-shaped
+    value in a delegated goal would surface in the sidebar / search results even
+    with `api_redact_enabled=True`. Shared by `_sidebar_session_response_item`
+    (`/api/sessions`) and every `/api/sessions/search` response branch so the two
+    endpoints can never drift on which fields get redacted.
+    """
+    for field in ("display_title", "_state_db_title", "parent_title"):
+        value = item.get(field)
+        if isinstance(value, str):
+            item[field] = _redact_text(value, _enabled=redact_enabled)
+
+
 # ── Login page locale strings ─────────────────────────────────────────────────
 # Add entries here to support more languages on the login page.
 # The key must match the 'language' setting value (from static/i18n.js LOCALES).
@@ -16581,12 +16587,21 @@ def _handle_sessions_search(handler, parsed):
         depth = max(0, int(qs.get("depth", ["5"])[0]))
     except (ValueError, TypeError):
         depth = 5
+    # Read the redaction setting ONCE for the whole response (mirrors the
+    # /api/sessions read-once optimization, #4662) and thread it through every
+    # branch + the shared title-field redactor so search rows redact the same
+    # fields as the sidebar list.
+    try:
+        _search_redact_enabled = bool(load_settings().get("api_redact_enabled", True))
+    except Exception:
+        _search_redact_enabled = True  # fail safe: redact when settings unreadable
     if not q:
         safe_sessions = []
         for s in sessions:
             item = dict(s)
             if isinstance(item.get("title"), str):
-                item["title"] = _redact_text(item["title"])
+                item["title"] = _redact_text(item["title"], _enabled=_search_redact_enabled)
+            _redact_sidebar_title_fields(item, _search_redact_enabled)
             safe_sessions.append(item)
         return j(handler, {
             "sessions": safe_sessions,
@@ -16599,7 +16614,8 @@ def _handle_sessions_search(handler, parsed):
         if title_match:
             item = dict(s, match_type="title")
             if isinstance(item.get("title"), str):
-                item["title"] = _redact_text(item["title"])
+                item["title"] = _redact_text(item["title"], _enabled=_search_redact_enabled)
+            _redact_sidebar_title_fields(item, _search_redact_enabled)
             results.append(item)
             continue
         if content_search:
@@ -16612,9 +16628,10 @@ def _handle_sessions_search(handler, parsed):
                         item = dict(s, match_type="content")
                         preview = _session_search_preview(c, q)
                         if preview:
-                            item["match_preview"] = _redact_text(preview)
+                            item["match_preview"] = _redact_text(preview, _enabled=_search_redact_enabled)
                         if isinstance(item.get("title"), str):
-                            item["title"] = _redact_text(item["title"])
+                            item["title"] = _redact_text(item["title"], _enabled=_search_redact_enabled)
+                        _redact_sidebar_title_fields(item, _search_redact_enabled)
                         results.append(item)
                         break
             except (KeyError, Exception):

tests/test_issue4662_sidebar_redaction_read_once.py

@@ -90,3 +90,41 @@ def test_sidebar_payload_redacts_display_and_parent_titles(monkeypatch):
         assert secret not in str(row.get(field, "")), (
             f"credential leaked into sidebar {field}: {row.get(field)!r}"
         )
+
+
+def test_redact_sidebar_title_fields_helper():
+    """The shared helper redacts every user-content-derived title field, honors the
+    enabled flag, and never raises on missing/non-str fields."""
+    secret = "sk-" + ("B" * 44)
+    item = {
+        "title": "kept-by-caller",
+        "display_title": f"a {secret}",
+        "_state_db_title": f"b {secret}",
+        "parent_title": f"c {secret}",
+        "session_id": "s1",
+    }
+    routes._redact_sidebar_title_fields(item, True)
+    for field in ("display_title", "_state_db_title", "parent_title"):
+        assert secret not in item[field], f"{field} not redacted"
+    # Disabled → pass through unchanged.
+    item2 = {"display_title": f"a {secret}"}
+    routes._redact_sidebar_title_fields(item2, False)
+    assert item2["display_title"] == f"a {secret}"
+    # Missing / non-str fields must not raise.
+    routes._redact_sidebar_title_fields({"display_title": None, "parent_title": 42}, True)
+
+
+def test_sessions_search_branches_redact_derived_titles():
+    """Every /api/sessions/search response branch must call the shared title-field
+    redactor so search rows can't leak a derived display_title the sidebar hides.
+    Source-guard: the #6056 class-fix is easy to regress by adding a 4th branch."""
+    import inspect
+    src = inspect.getsource(routes._handle_sessions_search)
+    # 3 response branches (empty-query list, title-match, content-match) each build
+    # an `item` and must pass it through _redact_sidebar_title_fields.
+    assert src.count("_redact_sidebar_title_fields(item") >= 3, (
+        "a /api/sessions/search branch builds a row without redacting the derived "
+        "title fields (display_title/_state_db_title/parent_title)"
+    )
+    # And it must read the setting once, not per-_redact_text call.
+    assert "_search_redact_enabled" in src