gh-159880: Fix handle leak in winreg when audit hook returns failure (GH-159881)

Author: aisk

Misc/NEWS.d/next/Windows/2026-10-20-21-37-34.gh-issue-159880.eKBiLr.rst

@@ -0,0 +1,3 @@
+Fix a key handle leak in :func:`winreg.CreateKey`,
+:func:`winreg.CreateKeyEx` and :func:`winreg.OpenKey` when the
+``winreg.OpenKey/result`` audit hook fails.

PC/winreg.c

@@ -900,6 +900,7 @@ winreg_CreateKey_impl(PyObject *module, HKEY key, const wchar_t *sub_key)
     }
     if (PySys_Audit("winreg.OpenKey/result", "n",
                     (Py_ssize_t)retKey) < 0) {
+        RegCloseKey(retKey);
         return NULL;
     }
     return retKey;
@@ -952,6 +953,7 @@ winreg_CreateKeyEx_impl(PyObject *module, HKEY key, const wchar_t *sub_key,
     }
     if (PySys_Audit("winreg.OpenKey/result", "n",
                     (Py_ssize_t)retKey) < 0) {
+        RegCloseKey(retKey);
         return NULL;
     }
     return retKey;
@@ -1398,6 +1400,7 @@ winreg_OpenKey_impl(PyObject *module, HKEY key, const wchar_t *sub_key,
     }
     if (PySys_Audit("winreg.OpenKey/result", "n",
                     (Py_ssize_t)retKey) < 0) {
+        RegCloseKey(retKey);
         return NULL;
     }
     return retKey;