[3.11] gh-97728: Argument Clinic: Fix uninitialized variable in the Py_UNICODE converter (GH-97729) (GH-97757)

It affects function os.system() on Windows and Windows-specific modules
winreg, _winapi, _overlapped, and _msi.
(cherry picked from commit 0ee9619a4cba58730c45e65d22288fadbf7680de)

2 files changed, 22 insertions, 22 deletions

diff --git a/PC/clinic/_msi.c.h b/PC/clinic/_msi.c.h
index fd21142..b717192 100644
--- a/PC/clinic/_msi.c.h
+++ b/PC/clinic/_msi.c.h
@@ -195,7 +195,7 @@ _msi_Record_SetString(msiobj *self, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     int field;
-    const Py_UNICODE *value;
+    const Py_UNICODE *value = NULL;
 
     if (!_PyArg_CheckPositional("SetString", nargs, 2, 2)) {
         goto exit;
@@ -244,7 +244,7 @@ _msi_Record_SetStream(msiobj *self, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     int field;
-    const Py_UNICODE *value;
+    const Py_UNICODE *value = NULL;
 
     if (!_PyArg_CheckPositional("SetStream", nargs, 2, 2)) {
         goto exit;
@@ -555,7 +555,7 @@ static PyObject *
 _msi_Database_OpenView(msiobj *self, PyObject *arg)
 {
     PyObject *return_value = NULL;
-    const Py_UNICODE *sql;
+    const Py_UNICODE *sql = NULL;
 
     if (!PyUnicode_Check(arg)) {
         _PyArg_BadArgument("OpenView", "argument", "str", arg);
@@ -650,7 +650,7 @@ static PyObject *
 _msi_OpenDatabase(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
-    const Py_UNICODE *path;
+    const Py_UNICODE *path = NULL;
     int persist;
 
     if (!_PyArg_CheckPositional("OpenDatabase", nargs, 2, 2)) {
@@ -713,4 +713,4 @@ _msi_CreateRecord(PyObject *module, PyObject *arg)
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=d7eb07e6bfcdc13f input=a9049054013a1b77]*/
+/*[clinic end generated code: output=276175d60fbfc956 input=a9049054013a1b77]*/
diff --git a/PC/clinic/winreg.c.h b/PC/clinic/winreg.c.h
index 2507e46..a413dec 100644
--- a/PC/clinic/winreg.c.h
+++ b/PC/clinic/winreg.c.h
@@ -148,7 +148,7 @@ static PyObject *
 winreg_ConnectRegistry(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
-    const Py_UNICODE *computer_name;
+    const Py_UNICODE *computer_name = NULL;
     HKEY key;
     HKEY _return_value;
 
@@ -220,7 +220,7 @@ winreg_CreateKey(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    const Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key = NULL;
     HKEY _return_value;
 
     if (!_PyArg_CheckPositional("CreateKey", nargs, 2, 2)) {
@@ -301,7 +301,7 @@ winreg_CreateKeyEx(PyObject *module, PyObject *const *args, Py_ssize_t nargs, Py
     static const char * const _keywords[] = {"key", "sub_key", "reserved", "access", NULL};
     static _PyArg_Parser _parser = {"O&O&|ii:CreateKeyEx", _keywords, 0};
     HKEY key;
-    const Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key = NULL;
     int reserved = 0;
     REGSAM access = KEY_WRITE;
     HKEY _return_value;
@@ -354,7 +354,7 @@ winreg_DeleteKey(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    const Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key = NULL;
 
     if (!_PyArg_CheckPositional("DeleteKey", nargs, 2, 2)) {
         goto exit;
@@ -428,7 +428,7 @@ winreg_DeleteKeyEx(PyObject *module, PyObject *const *args, Py_ssize_t nargs, Py
     static const char * const _keywords[] = {"key", "sub_key", "access", "reserved", NULL};
     static _PyArg_Parser _parser = {"O&O&|ii:DeleteKeyEx", _keywords, 0};
     HKEY key;
-    const Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key = NULL;
     REGSAM access = KEY_WOW64_64KEY;
     int reserved = 0;
 
@@ -469,7 +469,7 @@ winreg_DeleteValue(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    const Py_UNICODE *value;
+    const Py_UNICODE *value = NULL;
 
     if (!_PyArg_CheckPositional("DeleteValue", nargs, 2, 2)) {
         goto exit;
@@ -619,7 +619,7 @@ static PyObject *
 winreg_ExpandEnvironmentStrings(PyObject *module, PyObject *arg)
 {
     PyObject *return_value = NULL;
-    const Py_UNICODE *string;
+    const Py_UNICODE *string = NULL;
 
     if (!PyUnicode_Check(arg)) {
         _PyArg_BadArgument("ExpandEnvironmentStrings", "argument", "str", arg);
@@ -724,8 +724,8 @@ winreg_LoadKey(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    const Py_UNICODE *sub_key;
-    const Py_UNICODE *file_name;
+    const Py_UNICODE *sub_key = NULL;
+    const Py_UNICODE *file_name = NULL;
 
     if (!_PyArg_CheckPositional("LoadKey", nargs, 3, 3)) {
         goto exit;
@@ -805,7 +805,7 @@ winreg_OpenKey(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObje
     static const char * const _keywords[] = {"key", "sub_key", "reserved", "access", NULL};
     static _PyArg_Parser _parser = {"O&O&|ii:OpenKey", _keywords, 0};
     HKEY key;
-    const Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key = NULL;
     int reserved = 0;
     REGSAM access = KEY_READ;
     HKEY _return_value;
@@ -862,7 +862,7 @@ winreg_OpenKeyEx(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyOb
     static const char * const _keywords[] = {"key", "sub_key", "reserved", "access", NULL};
     static _PyArg_Parser _parser = {"O&O&|ii:OpenKeyEx", _keywords, 0};
     HKEY key;
-    const Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key = NULL;
     int reserved = 0;
     REGSAM access = KEY_READ;
     HKEY _return_value;
@@ -953,7 +953,7 @@ winreg_QueryValue(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    const Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key = NULL;
 
     if (!_PyArg_CheckPositional("QueryValue", nargs, 2, 2)) {
         goto exit;
@@ -1016,7 +1016,7 @@ winreg_QueryValueEx(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    const Py_UNICODE *name;
+    const Py_UNICODE *name = NULL;
 
     if (!_PyArg_CheckPositional("QueryValueEx", nargs, 2, 2)) {
         goto exit;
@@ -1084,7 +1084,7 @@ winreg_SaveKey(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    const Py_UNICODE *file_name;
+    const Py_UNICODE *file_name = NULL;
 
     if (!_PyArg_CheckPositional("SaveKey", nargs, 2, 2)) {
         goto exit;
@@ -1153,7 +1153,7 @@ winreg_SetValue(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    const Py_UNICODE *sub_key;
+    const Py_UNICODE *sub_key = NULL;
     DWORD type;
     PyObject *value_obj;
 
@@ -1228,7 +1228,7 @@ winreg_SetValueEx(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
 {
     PyObject *return_value = NULL;
     HKEY key;
-    const Py_UNICODE *value_name;
+    const Py_UNICODE *value_name = NULL;
     PyObject *reserved;
     DWORD type;
     PyObject *value;
@@ -1349,4 +1349,4 @@ winreg_QueryReflectionKey(PyObject *module, PyObject *arg)
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=7ad1db69bc42cab4 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=e83bdaabb4fa2167 input=a9049054013a1b77]*/