Hide ui.-prefixed knowls from the public knowl index (LMFDB#3721)

Knowls whose id starts with "ui." are user-interface helper texts
(search-box help bubbles, sort-order and statistics-extent
explanations, section landing-page intros) rather than context-free
definitions, and should not clutter the public knowl browse/search
index.

In lmfdb/knowledge/main.py index(), when the visitor is not logged in,
drop knowls whose id starts with "ui." from the search results before
categories are counted, so the "ui" category never appears publicly;
also reset an explicit ?category=ui request to the empty category so no
empty "ui" bucket is seeded.  Logged-in editors still see everything.

Verified with a logged-out flask test client: new lmfdb/knowledge/
test_knowledge.py patches knowldb.search to inject a synthetic ui.*
knowl and asserts it (and its category) are hidden when logged out and
shown when authenticated; the real /knowledge/ index still returns 200
with no "ui" category.  pyflakes clean; existing test_dynamic_knowls
tests still pass.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: roed314

lmfdb/knowledge/main.py

@@ -871,6 +871,15 @@ def index():
         else:
             flash_error("Unexpected error %s occurred during knowl search", str(e))
         all_knowls = []
+    # Knowls whose id starts with "ui." (e.g. search-box help bubbles, sort-order
+    # or statistics-extent explanations) are user-interface helper texts rather
+    # than context-free definitions.  They should not clutter the public knowl
+    # browse/search index, so we hide them -- and their "ui" category -- from
+    # visitors who are not logged in.  See LMFDB issue #3721.
+    if not current_user.is_authenticated:
+        all_knowls = [k for k in all_knowls if not k["id"].startswith("ui.")]
+        if cur_cat == "ui":
+            cur_cat = ""
     categories = Counter()
     if cur_cat:
         # Always include the current category

lmfdb/knowledge/test_knowledge.py

@@ -0,0 +1,73 @@
+# Tests for the knowledge (knowl) blueprint.
+
+from lmfdb.tests import LmfdbTest
+from lmfdb.knowledge import main as knowl_main
+
+
+class KnowlUIVisibilityTest(LmfdbTest):
+    """
+    Issue #3721: knowls whose id starts with ``ui.`` are user-interface helper
+    texts (search-box help, sort-order and statistics-extent explanations, ...)
+    rather than context-free definitions.  They must be hidden from the public
+    (logged-out) knowl browse/search index, together with their ``ui`` category.
+    """
+
+    # Stand-in for a knowldb.search() response: one ui. helper and one ordinary
+    # (context-free) math-definition knowl.
+    _fake_knowls = [
+        {"id": "ui.demo_helper", "title": "Demo UI helper"},
+        {"id": "ec.q.conductor", "title": "Conductor of an elliptic curve"},
+    ]
+
+    def _get_index(self):
+        """Render /knowledge/ with knowldb.search patched to return _fake_knowls."""
+        knowl_main.knowldb.search = lambda *args, **kwargs: [dict(k) for k in self._fake_knowls]
+        try:
+            return self.tc.get("/knowledge/", follow_redirects=True).get_data(as_text=True)
+        finally:
+            # Remove the instance override, restoring the real bound method.
+            del knowl_main.knowldb.search
+
+    def test_index_page_loads(self):
+        # Regression: the public knowl index still renders.
+        page = self.tc.get("/knowledge/", follow_redirects=True).get_data(as_text=True)
+        assert "Knowledge database" in page
+
+    def test_ui_knowl_hidden_when_logged_out(self):
+        page = self._get_index()
+        # The ui. helper and its "ui" category are hidden from a logged-out user ...
+        assert "ui.demo_helper" not in page
+        assert "ui(1)" not in page
+        # ... while ordinary knowls and their categories remain visible.
+        assert "ec.q.conductor" in page
+        assert "ec(1)" in page
+
+    def test_ui_category_query_hidden_when_logged_out(self):
+        # Explicitly requesting ?category=ui must not surface an empty "ui" category.
+        knowl_main.knowldb.search = lambda *args, **kwargs: [dict(k) for k in self._fake_knowls]
+        try:
+            page = self.tc.get("/knowledge/?category=ui", follow_redirects=True).get_data(as_text=True)
+        finally:
+            del knowl_main.knowldb.search
+        assert "ui.demo_helper" not in page
+        assert "ui(0)" not in page
+        assert "ui(1)" not in page
+
+    def test_ui_knowl_visible_when_logged_in(self):
+        # When authenticated, the filter is skipped and ui. knowls are listed.
+        class _FakeUser:
+            is_authenticated = True
+
+            def is_admin(self):
+                return False
+
+        orig_user = knowl_main.current_user
+        knowl_main.current_user = _FakeUser()
+        knowl_main.knowldb.search = lambda *args, **kwargs: [dict(k) for k in self._fake_knowls]
+        try:
+            page = self.tc.get("/knowledge/", follow_redirects=True).get_data(as_text=True)
+        finally:
+            knowl_main.current_user = orig_user
+            del knowl_main.knowldb.search
+        assert "ui.demo_helper" in page
+        assert "ec.q.conductor" in page