add tests

src/zope/index/field/index.py

@@ -55,19 +55,19 @@ def index_doc(self, docid, value):
         """See interface IInjection"""
         rev_index = self._rev_index
         if docid in rev_index:
-            if docid in self._fwd_index.get(value, ()):
+            if value is not None and docid in self._fwd_index.get(value, ()):
                 # no need to index the doc, its already up to date
                 return
             # unindex doc if present
             self.unindex_doc(docid)
 
         if value is not None:
-                # Insert into forward index.
-                set = self._fwd_index.get(value)
-                if set is None:
-                    set = self.family.IF.TreeSet()
-                    self._fwd_index[value] = set
-                set.insert(docid)
+            # Insert into forward index.
+            set = self._fwd_index.get(value)
+            if set is None:
+                set = self.family.IF.TreeSet()
+                self._fwd_index[value] = set
+            set.insert(docid)
 
         # increment doc count
         self._num_docs.change(1)

src/zope/index/field/tests.py

@@ -311,6 +311,21 @@ def test_sort_badlimit(self):
         result = index.sort(c1, limit=0)
         self.assertRaises(ValueError, list, result)
 
+    def test_insert_none_value_does_not_raise_typeerror(self):
+        index = self._makeOne()
+        index.index_doc(1, None)
+
+    def test_insert_none_value_to_update_does_not_raise_typeerror(self):
+        index = self._makeOne()
+        index.index_doc(1, 5)
+        index.index_doc(1, None)
+
+    def test_insert_none_value_does_not_insert_into_forward_index(self):
+        index = self._makeOne()
+        index.index_doc(1, None)
+        self.assertEquals(len(index._fwd_index), 0)
+        self.assertEquals(len(index._rev_index), 1)
+
 def test_suite():
     return unittest.TestSuite((
         doctest.DocFileSuite('README.txt', optionflags=doctest.ELLIPSIS),