From: Georg Brandl <georg@python.org>
Date: Mon, 11 Aug 2008 09:07:59 +0000 (+0000)
Subject: - Issue #3537: Fix an assertion failure when an empty but presized dict
X-Git-Tag: v2.6b3~103
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1e13ea94a3da9fa2b60c24ff201c5ae69791572d;p=thirdparty%2FPython%2Fcpython.git

- Issue #3537: Fix an assertion failure when an empty but presized dict
  object was stored in the freelist.
---

diff --git a/Lib/test/test_dict.py b/Lib/test/test_dict.py
index b62237d9d6f1..f715657d3665 100644
--- a/Lib/test/test_dict.py
+++ b/Lib/test/test_dict.py
@@ -544,6 +544,17 @@ class DictTest(unittest.TestCase):
         resizing = True
         d[9] = 6
 
+    def test_empty_presized_dict_in_freelist(self):
+        # Bug #3537: if an empty but presized dict with a size larger
+        # than 7 was in the freelist, it triggered an assertion failure
+        try:
+            d = {'a': 1/0,  'b': None, 'c': None, 'd': None, 'e': None,
+                 'f': None, 'g': None, 'h': None}
+        except ZeroDivisionError:
+            pass
+        d = {}
+
+
 
 from test import mapping_tests
 
diff --git a/Misc/NEWS b/Misc/NEWS
index a197efc7a0e7..1c346545ba0d 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@ What's New in Python 2.6 beta 3?
 Core and Builtins
 -----------------
 
+- Issue #3537: Fix an assertion failure when an empty but presized dict
+  object was stored in the freelist.
+
 - Issue #1481296: Make long(float('nan')) and int(float('nan')) raise
   ValueError consistently across platforms.
 
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 038f3738d654..cc083f171674 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -241,6 +241,10 @@ PyDict_New(void)
 		_Py_NewReference((PyObject *)mp);
 		if (mp->ma_fill) {
 			EMPTY_TO_MINSIZE(mp);
+		} else {
+			/* At least set ma_table and ma_mask; these are wrong
+			   if an empty but presized dict is added to freelist */
+			INIT_NONZERO_DICT_SLOTS(mp);
 		}
 		assert (mp->ma_used == 0);
 		assert (mp->ma_table == mp->ma_smalltable);