[Python-checkins] cpython (merge 3.3 -> default): Issue #16230: Fix a crash in select.select() when one the lists changes size

[antoine.pitrou]

http://hg.python.org/cpython/rev/823898ef37ce
changeset:   80163:823898ef37ce
parent:      80159:ab65509b8443
parent:      80162:717660ec8f67
user:        Antoine Pitrou <solipsis at pitrou.net>
date:        Thu Nov 01 20:16:07 2012 +0100
summary:
  Issue #16230: Fix a crash in select.select() when one the lists changes size while iterated on.
Patch by Serhiy Storchaka.

files:
  Lib/test/test_select.py |  10 ++++++++++
  Misc/NEWS               |   3 +++
  Modules/selectmodule.c  |   6 ++----
  3 files changed, 15 insertions(+), 4 deletions(-)


diff --git a/Lib/test/test_select.py b/Lib/test/test_select.py
--- a/Lib/test/test_select.py
+++ b/Lib/test/test_select.py
@@ -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 --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -85,6 +85,9 @@
 Library
 -------
 
+- Issue #16230: Fix a crash in select.select() when one the lists changes
+  size while iterated on.  Patch by Serhiy Storchaka.
+
 - Issue #16228: Fix a crash in the json module where a list changes size
   while it is being encoded.  Patch by Serhiy Storchaka.
 
diff --git a/Modules/selectmodule.c b/Modules/selectmodule.c
--- a/Modules/selectmodule.c
+++ b/Modules/selectmodule.c
@@ -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 */

-- 
Repository URL: http://hg.python.org/cpython