diff -r 568312ea04fa Lib/test/test_select.py
--- a/Lib/test/test_select.py	Sun Oct 14 04:17:50 2012 +0200
+++ b/Lib/test/test_select.py	Sun Oct 14 13:40:08 2012 +0300
@@ -65,6 +65,16 @@
             self.fail('Unexpected return values from select():', rfd, wfd, xfd)
         p.close()
 
+    # Issue 16230: Crash on select resized list
+    def test_select_mutated(self):
+        a = []
+        class F:
+            def fileno(self):
+                del a[-1]
+                return sys.__stdout__.fileno()
+        a[:] = [F()] * 10
+        self.assertEqual(select.select([], a, []), ([], a[:5], []))
+
 def test_main():
     support.run_unittest(SelectTestCase)
     support.reap_children()
diff -r 568312ea04fa Modules/selectmodule.c
--- a/Modules/selectmodule.c	Sun Oct 14 04:17:50 2012 +0200
+++ b/Modules/selectmodule.c	Sun Oct 14 13:40:08 2012 +0300
@@ -84,7 +84,7 @@
 {
     int max = -1;
     int index = 0;
-    Py_ssize_t i, len = -1;
+    Py_ssize_t i;
     PyObject* fast_seq = NULL;
     PyObject* o = NULL;
 
@@ -95,9 +95,7 @@
     if (!fast_seq)
         return -1;
 
-    len = PySequence_Fast_GET_SIZE(fast_seq);
-
-    for (i = 0; i < len; i++)  {
+    for (i = 0; i < PySequence_Fast_GET_SIZE(fast_seq); i++)  {
         SOCKET v;
 
         /* any intervening fileno() calls could decr this refcnt */