diff -r 2a18f6b85da2 Doc/library/stdtypes.rst
--- a/Doc/library/stdtypes.rst	Sun Apr 12 18:47:56 2015 -0400
+++ b/Doc/library/stdtypes.rst	Mon Apr 13 10:13:03 2015 -0400
@@ -1082,7 +1082,7 @@
 Notes:
 
 (1)
-   *t* must have the same length as the slice it is replacing.
+   *t* must have the same length as the slice it is replacing or be empty.
 
 (2)
    The optional argument *i* defaults to ``-1``, so that by default the last
diff -r 2a18f6b85da2 Lib/test/list_tests.py
--- a/Lib/test/list_tests.py	Sun Apr 12 18:47:56 2015 -0400
+++ b/Lib/test/list_tests.py	Mon Apr 13 10:13:03 2015 -0400
@@ -562,6 +562,13 @@
         a = self.type2test(range(10))
         del a[::1000]
         self.assertEqual(a, self.type2test([1, 2, 3, 4, 5, 6, 7, 8, 9]))
+        #  deletion via assignment (issue #12606)
+        b = self.type2test([0,1,2,3,4,5])
+        b[1:5:2] = []
+        self.assertEqual(b, self.type2test([0, 2, 4, 5]))
+        b[::-2] = ()
+        self.assertEqual(b, self.type2test([0, 4]))
+        self.assertRaises(TypeError, b.__setitem__, slice(None, None, 2), None)
         #  assignment
         a = self.type2test(range(10))
         a[::2] = [-1]*5
diff -r 2a18f6b85da2 Lib/test/test_bytes.py
--- a/Lib/test/test_bytes.py	Sun Apr 12 18:47:56 2015 -0400
+++ b/Lib/test/test_bytes.py	Mon Apr 13 10:13:03 2015 -0400
@@ -13,6 +13,7 @@
 import pickle
 import tempfile
 import unittest
+import itertools
 
 import test.support
 import test.string_tests
@@ -990,7 +991,8 @@
         for start in indices:
             for stop in indices:
                 # Skip invalid step 0
-                for step in indices[1:]:
+                bool_states = itertools.cycle((True, False))
+                for step, using_del in zip(indices[1:], bool_states):
                     L = list(range(255))
                     b = bytearray(L)
                     # Make sure we have a slice of exactly the right length,
@@ -1001,9 +1003,14 @@
                     b[start:stop:step] = data
                     self.assertEqual(b, bytearray(L))
 
-                    del L[start:stop:step]
-                    del b[start:stop:step]
-                    self.assertEqual(b, bytearray(L))
+                    if using_del:
+                        del L[start:stop:step]
+                        del b[start:stop:step]
+                        self.assertEqual(b, bytearray(L))
+                    else:
+                        L[start:stop:step] = []
+                        b[start:stop:step] = []
+                        self.assertEqual(b, bytearray(L))
 
     def test_setslice_trap(self):
         # This test verifies that we correctly handle assigning self
diff -r 2a18f6b85da2 Objects/listobject.c
--- a/Objects/listobject.c	Sun Apr 12 18:47:56 2015 -0400
+++ b/Objects/listobject.c	Mon Apr 13 10:13:03 2015 -0400
@@ -2479,7 +2479,23 @@
             (step > 0 && start > stop))
             stop = start;
 
-        if (value == NULL) {
+        PyObject *seq;
+        if (value) {
+            /* protect against a[::-1] = a */
+            if (self == (PyListObject*)value) {
+                seq = list_slice((PyListObject*)value, 0,
+                                   PyList_GET_SIZE(value));
+            }
+            else {
+                seq = PySequence_Fast(value,
+                                      "must assign iterable "
+                                      "to extended slice");
+            }
+            if (!seq)
+                return -1;
+        }
+
+        if (value == NULL || PySequence_Fast_GET_SIZE(seq) == 0) {
             /* delete slice */
             PyObject **garbage;
             size_t cur;
@@ -2546,23 +2562,10 @@
         }
         else {
             /* assign slice */
-            PyObject *ins, *seq;
+            PyObject *ins;
             PyObject **garbage, **seqitems, **selfitems;
             Py_ssize_t cur, i;
 
-            /* protect against a[::-1] = a */
-            if (self == (PyListObject*)value) {
-                seq = list_slice((PyListObject*)value, 0,
-                                   PyList_GET_SIZE(value));
-            }
-            else {
-                seq = PySequence_Fast(value,
-                                      "must assign iterable "
-                                      "to extended slice");
-            }
-            if (!seq)
-                return -1;
-
             if (PySequence_Fast_GET_SIZE(seq) != slicelength) {
                 PyErr_Format(PyExc_ValueError,
                     "attempt to assign sequence of "