[Python-checkins] cpython (2.7): Issue #16230: Fix a crash in select.select() when one the lists changes size

[antoine.pitrou]

http://hg.python.org/cpython/rev/02a5322b0cee
changeset:   80164:02a5322b0cee
branch:      2.7
parent:      80160:33ae62a4ecf5
user:        Antoine Pitrou <solipsis at pitrou.net>
date:        Thu Nov 01 20:13:54 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 |  9 +++++++++
  Misc/NEWS               |  3 +++
  Modules/selectmodule.c  |  5 +----
  3 files changed, 13 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
@@ -49,6 +49,15 @@
             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():
     test_support.run_unittest(SelectTestCase)
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -130,6 +130,9 @@
 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
@@ -87,7 +87,6 @@
     int i;
     int max = -1;
     int index = 0;
-    int len = -1;
     PyObject* fast_seq = NULL;
     PyObject* o = NULL;
 
@@ -98,9 +97,7 @@
     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