faiss: fix IndexIDMap range_search crash with empty SearchParameters (#5388)

Summary:
Pull Request resolved: https://github.com/facebookresearch/faiss/pull/5388

IndexIDMap::range_search checked only if params is non-null, then
unconditionally constructed IDSelectorTranslated with params->sel.
When an empty SearchParameters() is passed, sel is nullptr, leading
to null dereference in IDSelectorTranslated::is_member -> crash/hang.

This mirrors the existing guard in search_ex which checks
params && params->sel. Update range_search to same logic and pass
through params when sel is null, so empty SearchParameters behaves
same as no params.

I also took a quick look at other search functions. They all use this pattern if they support IDSelector (some do not).

Fixes https://github.com/facebookresearch/faiss/issues/5332

Reviewed By: alibeklfc

Differential Revision: D110987904

fbshipit-source-id: 3d87625cfc733e9ff6c7352f13e167feceae8d76

faiss/IndexIDMap.cpp

@@ -228,14 +228,14 @@ void IndexIDMapTemplate<IndexT>::range_search(
         typename IndexT::distance_t radius,
         RangeSearchResult* result,
         const SearchParameters* params) const {
-    if (params) {
+    if (params && params->sel) {
         SearchParameters internal_search_parameters;
         IDSelectorTranslated id_selector_translated(id_map, params->sel);
         internal_search_parameters.sel = &id_selector_translated;
 
         index->range_search(n, x, radius, result, &internal_search_parameters);
     } else {
-        index->range_search(n, x, radius, result);
+        index->range_search(n, x, radius, result, params);
     }
 
     const idx_t id_map_size = static_cast<idx_t>(id_map.size());

tests/test_search_params.py

@@ -337,6 +337,32 @@ class TestSelector(unittest.TestCase):
         np.testing.assert_array_equal(Iref, Inew)
         np.testing.assert_array_almost_equal(Dref, Dnew, decimal=5)
 
+    def test_idmap_range_empty_params(self):
+        # This test crashes without checking both params && params->sel
+        # are non null in IndexIDMap::range_search().
+        index = faiss.IndexIDMap(faiss.IndexFlatL2(2))
+
+        xb = np.array(
+            [
+                [0, 0],
+                [1, 0],
+                [0, 2],
+            ],
+            dtype="float32",
+        )
+        ids = np.array([10, 20, 30], dtype="int64")
+        index.add_with_ids(xb, ids)
+        xq = np.array([[0, 0]], dtype="float32")
+
+        lims_ref, D_ref, I_ref = index.range_search(xq, 5.0)
+        lims, D, I = index.range_search(
+            xq, 5.0, params=faiss.SearchParameters()
+        )
+
+        np.testing.assert_array_equal(lims_ref, lims)
+        np.testing.assert_array_equal(sorted(I_ref), sorted(I))
+        np.testing.assert_array_equal(sorted(D_ref), sorted(D))
+
     def test_bounds(self):
         # https://github.com/facebookresearch/faiss/issues/3156
         d = 64  # dimension