Fix #14420. Use PyLong_AsUnsignedLong to support the full range of DWORD.

This fixes an OverflowError seen in winreg.SetValueEx when passed
winreg.REG_DWORD values that should be supported by the underlying API.

Lib/test/test_winreg.py

@@ -323,6 +323,18 @@ class LocalWinregTests(BaseWinregTests):
         finally:
             DeleteKey(HKEY_CURRENT_USER, test_key_name)
 
+    def test_setvalueex_value_range(self):
+        # Test for Issue #14420, accept proper ranges for SetValueEx.
+        # Py2Reg, which gets called by SetValueEx, was using PyLong_AsLong,
+        # thus raising OverflowError. The implementation now uses
+        # PyLong_AsUnsignedLong to match DWORD's size.
+        try:
+            with CreateKey(HKEY_CURRENT_USER, test_key_name) as ck:
+                self.assertNotEqual(ck.handle, 0)
+                SetValueEx(ck, "test_name", None, REG_DWORD, 0x80000000)
+        finally:
+            DeleteKey(HKEY_CURRENT_USER, test_key_name)
+
 
 @unittest.skipUnless(REMOTE_NAME, "Skipping remote registry tests")
 class RemoteWinregTests(BaseWinregTests):

Misc/NEWS

@@ -10,6 +10,9 @@ What's New in Python 3.2.4
 Core and Builtins
 -----------------
 
+- Issue #14420: Support the full DWORD (unsigned long) range in Py2Reg
+  when passed a REG_DWORD value. Fixes OverflowError in winreg.SetValueEx.
+
 - Issue #16602: When a weakref's target was part of a long deallocation
   chain, the object could remain reachable through its weakref even though
   its refcount had dropped to zero.

PC/winreg.c

@@ -785,7 +785,7 @@ Py2Reg(PyObject *value, DWORD typ, BYTE **retDataBuf, DWORD *retDataSize)
                 memcpy(*retDataBuf, &zero, sizeof(DWORD));
             }
             else {
-                DWORD d = PyLong_AsLong(value);
+                DWORD d = PyLong_AsUnsignedLong(value);
                 memcpy(*retDataBuf, &d, sizeof(DWORD));
             }
             break;