bpo-35445: Do not ignore memory errors when create posix.environ. (GH-11049)

Misc/NEWS.d/next/Library/2018-12-09-14-35-49.bpo-35445.LjvtsC.rst

+Memory errors during creating posix.environ no longer ignored.

Modules/posixmodule.c

@@ -1356,62 +1356,52 @@ convertenviron(void)
     /* _wenviron must be initialized in this way if the program is started
        through main() instead of wmain(). */
     _wgetenv(L"");
-    if (_wenviron == NULL)
+    e = _wenviron;
+#else
+    e = environ;
+#endif
+    if (e == NULL)
         return d;
-    /* This part ignores errors */
-    for (e = _wenviron; *e != NULL; e++) {
+    for (; *e != NULL; e++) {
         PyObject *k;
         PyObject *v;
+#ifdef MS_WINDOWS
         const wchar_t *p = wcschr(*e, L'=');
-        if (p == NULL)
-            continue;
-        k = PyUnicode_FromWideChar(*e, (Py_ssize_t)(p-*e));
-        if (k == NULL) {
-            PyErr_Clear();
-            continue;
-        }
-        v = PyUnicode_FromWideChar(p+1, wcslen(p+1));
-        if (v == NULL) {
-            PyErr_Clear();
-            Py_DECREF(k);
-            continue;
-        }
-        if (PyDict_GetItem(d, k) == NULL) {
-            if (PyDict_SetItem(d, k, v) != 0)
-                PyErr_Clear();
-        }
-        Py_DECREF(k);
-        Py_DECREF(v);
-    }
 #else
-    if (environ == NULL)
-        return d;
-    /* This part ignores errors */
-    for (e = environ; *e != NULL; e++) {
-        PyObject *k;
-        PyObject *v;
         const char *p = strchr(*e, '=');
+#endif
         if (p == NULL)
             continue;
+#ifdef MS_WINDOWS
+        k = PyUnicode_FromWideChar(*e, (Py_ssize_t)(p-*e));
+#else
         k = PyBytes_FromStringAndSize(*e, (int)(p-*e));
+#endif
         if (k == NULL) {
-            PyErr_Clear();
-            continue;
+            Py_DECREF(d);
+            return NULL;
         }
+#ifdef MS_WINDOWS
+        v = PyUnicode_FromWideChar(p+1, wcslen(p+1));
+#else
         v = PyBytes_FromStringAndSize(p+1, strlen(p+1));
+#endif
         if (v == NULL) {
-            PyErr_Clear();
             Py_DECREF(k);
-            continue;
+            Py_DECREF(d);
+            return NULL;
         }
-        if (PyDict_GetItem(d, k) == NULL) {
-            if (PyDict_SetItem(d, k, v) != 0)
-                PyErr_Clear();
+        if (PyDict_GetItemWithError(d, k) == NULL) {
+            if (PyErr_Occurred() || PyDict_SetItem(d, k, v) != 0) {
+                Py_DECREF(v);
+                Py_DECREF(k);
+                Py_DECREF(d);
+                return NULL;
+            }
         }
         Py_DECREF(k);
         Py_DECREF(v);
     }
-#endif
     return d;
 }