gh-108308: Use PyDict_GetItemRef() in moduleobject.c (#108381)

Replace PyDict_GetItemWithError() with PyDict_GetItemRef() which
returns a strong reference.

Cleanup also the function: move variable definition to their first
assignation, rename variable names to use name longer than 1
character.

1 files changed, 40 insertions, 28 deletions

diff --git a/Objects/moduleobject.c b/Objects/moduleobject.c
index 7e890d0..5b9f74d 100644
--- a/Objects/moduleobject.c
+++ b/Objects/moduleobject.c
@@ -510,25 +510,31 @@ PyModule_GetDict(PyObject *m)
 }
 
 PyObject*
-PyModule_GetNameObject(PyObject *m)
+PyModule_GetNameObject(PyObject *mod)
 {
-    PyObject *d;
-    PyObject *name;
-    if (!PyModule_Check(m)) {
+    if (!PyModule_Check(mod)) {
         PyErr_BadArgument();
         return NULL;
     }
-    d = ((PyModuleObject *)m)->md_dict;
-    if (d == NULL || !PyDict_Check(d) ||
-        (name = PyDict_GetItemWithError(d, &_Py_ID(__name__))) == NULL ||
-        !PyUnicode_Check(name))
-    {
-        if (!PyErr_Occurred()) {
-            PyErr_SetString(PyExc_SystemError, "nameless module");
-        }
-        return NULL;
+    PyObject *dict = ((PyModuleObject *)mod)->md_dict;  // borrowed reference
+    if (dict == NULL || !PyDict_Check(dict)) {
+        goto error;
+    }
+    PyObject *name;
+    if (PyDict_GetItemRef(dict, &_Py_ID(__name__), &name) <= 0) {
+        goto error;
+    }
+    if (!PyUnicode_Check(name)) {
+        Py_DECREF(name);
+        goto error;
+    }
+    return name;
+
+error:
+    if (!PyErr_Occurred()) {
+        PyErr_SetString(PyExc_SystemError, "nameless module");
     }
-    return Py_NewRef(name);
+    return NULL;
 }
 
 const char *
@@ -544,25 +550,31 @@ PyModule_GetName(PyObject *m)
 }
 
 PyObject*
-PyModule_GetFilenameObject(PyObject *m)
+PyModule_GetFilenameObject(PyObject *mod)
 {
-    PyObject *d;
-    PyObject *fileobj;
-    if (!PyModule_Check(m)) {
+    if (!PyModule_Check(mod)) {
         PyErr_BadArgument();
         return NULL;
     }
-    d = ((PyModuleObject *)m)->md_dict;
-    if (d == NULL ||
-        (fileobj = PyDict_GetItemWithError(d, &_Py_ID(__file__))) == NULL ||
-        !PyUnicode_Check(fileobj))
-    {
-        if (!PyErr_Occurred()) {
-            PyErr_SetString(PyExc_SystemError, "module filename missing");
-        }
-        return NULL;
+    PyObject *dict = ((PyModuleObject *)mod)->md_dict;  // borrowed reference
+    if (dict == NULL) {
+        goto error;
     }
-    return Py_NewRef(fileobj);
+    PyObject *fileobj;
+    if (PyDict_GetItemRef(dict, &_Py_ID(__file__), &fileobj) <= 0) {
+        goto error;
+    }
+    if (!PyUnicode_Check(fileobj)) {
+        Py_DECREF(fileobj);
+        goto error;
+    }
+    return fileobj;
+
+error:
+    if (!PyErr_Occurred()) {
+        PyErr_SetString(PyExc_SystemError, "module filename missing");
+    }
+    return NULL;
 }
 
 const char *