handle dict subclasses gracefully in PyArg_ValidateKeywordArguments

benjaminp · benjaminp · commit f609654b0e36 · 2010-11-17T22:33:12.000Z
diff --git a/Lib/test/test_dict.py b/Lib/test/test_dict.py
@@ -8,10 +8,13 @@
 class DictTest(unittest.TestCase):
 
     def test_invalid_keyword_arguments(self):
-        with self.assertRaises(TypeError):
-            dict(**{1 : 2})
-        with self.assertRaises(TypeError):
-            {}.update(**{1 : 2})
+        class Custom(dict):
+            pass
+        for invalid in {1 : 2}, Custom({1 : 2}):
+            with self.assertRaises(TypeError):
+                dict(**invalid)
+            with self.assertRaises(TypeError):
+                {}.update(**invalid)
 
     def test_constructor(self):
         # calling built-in types without argument must return empty
diff --git a/Misc/NEWS b/Misc/NEWS
@@ -26,6 +26,11 @@ Library
 - Issue #10429: IMAP.starttls() stored the capabilities as bytes objects,
   rather than strings.
 
+C-API
+-----
+
+- Loosen PyArg_ValidateKeywordArguments to allow dict subclasses.
+
 
 What's New in Python 3.2 Alpha 4?
 =================================
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
@@ -454,7 +454,7 @@ _PyDict_HasOnlyStringKeys(PyObject *dict)
 {
     Py_ssize_t pos = 0;
     PyObject *key, *value;
-    assert(PyDict_CheckExact(dict));
+    assert(PyDict_Check(dict));
     /* Shortcut */
     if (((PyDictObject *)dict)->ma_lookup == lookdict_unicode)
         return 1;
diff --git a/Python/getargs.c b/Python/getargs.c
@@ -1394,7 +1394,7 @@ _PyArg_VaParseTupleAndKeywords_SizeT(PyObject *args,
 int
 PyArg_ValidateKeywordArguments(PyObject *kwargs)
 {
-    if (!PyDict_CheckExact(kwargs)) {
+    if (!PyDict_Check(kwargs)) {
         PyErr_BadInternalCall();
         return 0;
     }

Original file line number	Diff line number	Diff line change
`@@ -454,7 +454,7 @@ _PyDict_HasOnlyStringKeys(PyObject *dict)`
`454`	`454`	`{`
`455`	`455`	`Py_ssize_t pos = 0;`
`456`	`456`	`PyObject key, value;`
`457`		`- assert(PyDict_CheckExact(dict));`
	`457`	`+ assert(PyDict_Check(dict));`
`458`	`458`	`/* Shortcut */`
`459`	`459`	`if (((PyDictObject *)dict)->ma_lookup == lookdict_unicode)`
`460`	`460`	`return 1;`
Original file line number	Diff line number	Diff line change
`@@ -1394,7 +1394,7 @@ _PyArg_VaParseTupleAndKeywords_SizeT(PyObject *args,`
`1394`	`1394`	`int`
`1395`	`1395`	`PyArg_ValidateKeywordArguments(PyObject *kwargs)`
`1396`	`1396`	`{`
`1397`		`- if (!PyDict_CheckExact(kwargs)) {`
	`1397`	`+ if (!PyDict_Check(kwargs)) {`
`1398`	`1398`	`PyErr_BadInternalCall();`
`1399`	`1399`	`return 0;`
`1400`	`1400`	`}`