From 0661e91feda0757c10c8b3bf3fa047b7d3e50444 Mon Sep 17 00:00:00 2001
From: Raymond Hettinger <python@rcn.com>
Date: Tue, 15 Mar 2011 15:03:36 -0700
Subject: [PATCH 1/3] Issue 11510: Fix BUILD_SET optimizer bug.

---
 Lib/test/test_peepholer.py | 14 +++++++++++++-
 Python/peephole.c          |  3 ++-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/Lib/test/test_peepholer.py b/Lib/test/test_peepholer.py
index a9eb23fde31..a40b4b7a01f 100644
--- a/Lib/test/test_peepholer.py
+++ b/Lib/test/test_peepholer.py
@@ -294,11 +294,23 @@ class TestTranforms(unittest.TestCase):
             self.assertNotIn('BINARY_', asm, e)
             self.assertNotIn('BUILD_', asm, e)
 
+class TestBuglets(unittest.TestCase):
+
+     def test_bug_11510(self):
+         # folded constant set optimization was commingled with the tuple
+         # unpacking optimization which would fail if the set had duplicate
+         # elements so that the set length was unexpected
+         def f():
+             x, y = {1, 1}
+             return x, y
+         with self.assertRaises(ValueError):
+             f()
+
 
 def test_main(verbose=None):
     import sys
     from test import support
-    test_classes = (TestTranforms,)
+    test_classes = (TestTranforms, TestBuglets)
     support.run_unittest(*test_classes)
 
     # verify reference counting
diff --git a/Python/peephole.c b/Python/peephole.c
index ab96ce9def2..4bc65dcc312 100644
--- a/Python/peephole.c
+++ b/Python/peephole.c
@@ -535,7 +535,8 @@ PyCode_Optimize(PyObject *code, PyObject* consts, PyObject *names,
                 }
                 if (codestr[i+3] != UNPACK_SEQUENCE  ||
                     !ISBASICBLOCK(blocks,i,6) ||
-                    j != GETARG(codestr, i+3))
+                    j != GETARG(codestr, i+3) ||
+                    opcode == BUILD_SET)
                     continue;
                 if (j == 1) {
                     memset(codestr+i, NOP, 6);

From f932f747e6242c7de88864798e845135d9d981c9 Mon Sep 17 00:00:00 2001
From: Raymond Hettinger <python@rcn.com>
Date: Tue, 15 Mar 2011 15:06:09 -0700
Subject: [PATCH 2/3] whitespace fix

---
 Lib/test/test_peepholer.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Lib/test/test_peepholer.py b/Lib/test/test_peepholer.py
index a40b4b7a01f..bab4c1e5d9d 100644
--- a/Lib/test/test_peepholer.py
+++ b/Lib/test/test_peepholer.py
@@ -19,6 +19,7 @@ def disassemble(func):
 def dis_single(line):
     return disassemble(compile(line, '', 'single'))
 
+
 class TestTranforms(unittest.TestCase):
 
     def test_unot(self):

From 5bd75b87263bc6502753381138e15531ce4574a6 Mon Sep 17 00:00:00 2001
From: Raymond Hettinger <python@rcn.com>
Date: Tue, 15 Mar 2011 15:07:38 -0700
Subject: [PATCH 3/3] whitespace fix

---
 Lib/test/test_peepholer.py | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/Lib/test/test_peepholer.py b/Lib/test/test_peepholer.py
index bab4c1e5d9d..f73565eb46f 100644
--- a/Lib/test/test_peepholer.py
+++ b/Lib/test/test_peepholer.py
@@ -297,15 +297,15 @@ class TestTranforms(unittest.TestCase):
 
 class TestBuglets(unittest.TestCase):
 
-     def test_bug_11510(self):
-         # folded constant set optimization was commingled with the tuple
-         # unpacking optimization which would fail if the set had duplicate
-         # elements so that the set length was unexpected
-         def f():
-             x, y = {1, 1}
-             return x, y
-         with self.assertRaises(ValueError):
-             f()
+    def test_bug_11510(self):
+        # folded constant set optimization was commingled with the tuple
+        # unpacking optimization which would fail if the set had duplicate
+        # elements so that the set length was unexpected
+        def f():
+            x, y = {1, 1}
+            return x, y
+        with self.assertRaises(ValueError):
+            f()
 
 
 def test_main(verbose=None):