bpo-41662: Fix bugs in binding parameters in sqlite3 (GH-21998)


* When the parameters argument is a list, correctly handle the case
  of changing it during iteration.
* When the parameters argument is a custom sequence, no longer
  override an exception raised in ``__len__()``.
(cherry picked from commit 0b419b791077414bbc011a412698ebb362b63761)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
diff --git a/Lib/sqlite3/test/dbapi.py b/Lib/sqlite3/test/dbapi.py
index be11337..ad9c9f0 100644
--- a/Lib/sqlite3/test/dbapi.py
+++ b/Lib/sqlite3/test/dbapi.py
@@ -276,7 +276,7 @@
         self.assertEqual(row[0], "foo")
 
     def CheckExecuteParamSequence(self):
-        class L(object):
+        class L:
             def __len__(self):
                 return 1
             def __getitem__(self, x):
@@ -288,6 +288,18 @@
         row = self.cu.fetchone()
         self.assertEqual(row[0], "foo")
 
+    def CheckExecuteParamSequenceBadLen(self):
+        # Issue41662: Error in __len__() was overridden with ProgrammingError.
+        class L:
+            def __len__(self):
+                1/0
+            def __getitem__(slf, x):
+                raise AssertionError
+
+        self.cu.execute("insert into test(name) values ('foo')")
+        with self.assertRaises(ZeroDivisionError):
+            self.cu.execute("select name from test where name=?", L())
+
     def CheckExecuteDictMapping(self):
         self.cu.execute("insert into test(name) values ('foo')")
         self.cu.execute("select name from test where name=:name", {"name": "foo"})