refactor PluginIndexes.unindex.UnIndex.query_index fixing #55 and #56

CHANGES.rst

@@ -4,6 +4,11 @@ Changelog
 4.4 (unreleased)
 ----------------
 
+- Refactor ``Products.PluginIndexes.unindex.Unindex.query_index``
+  (`#56 <https://github.com/zopefoundation/Products.ZCatalog/issues/56>`_)
+  and fix
+  (`#55 <https://github.com/zopefoundation/Products.ZCatalog/issues/55>`_).
+
 - Specify supported Python versions using ``python_requires`` in setup.py
   (`Zope#481 <https://github.com/zopefoundation/Zope/issues/481>`_)
 

src/Products/PluginIndexes/FieldIndex/FieldIndex.py

@@ -21,6 +21,7 @@ class FieldIndex(UnIndex):
     """
     meta_type = 'FieldIndex'
     query_options = ('query', 'range', 'not')
+    potentially_multivalued = False  # optimization for exclude terms
 
     manage_options = (
         {'label': 'Settings', 'action': 'manage_main'},

src/Products/PluginIndexes/tests/test_unindex.py

@@ -13,7 +13,7 @@
 
 import unittest
 
-from BTrees.IIBTree import difference
+from BTrees.IIBTree import difference, IISet
 from OFS.SimpleItem import SimpleItem
 from Testing.makerequest import makerequest
 
@@ -193,3 +193,16 @@ class Dummy(object):
         query = IndexQuery({'counter': 42}, 'counter')
         res = index.query_index(query)
         self.assertListEqual(list(res), [])
+
+    def test_resultset_intersection(self):
+        """see #55
+        `https://github.com/zopefoundation/Products.ZCatalog/issues/55`.
+        """
+        index = self._makeOne("rsi")
+        for i in (1, 2):
+            index.insertForwardIndexEntry(i, i)
+        ers = IISet()  # empty result set
+        for q in ((1,), (1, 2)):
+            qd = dict(rsi=dict(query=q))
+            self.assertEqual(q, tuple(index._apply_index(qd)[0]))
+            self.assertEqual((), tuple(index._apply_index(qd, ers)[0]))