bpo-44113: Update

Author: corona10

Modules/_xxtestfuzz/fuzzer.c

@@ -412,17 +412,22 @@ int __lsan_is_turned_off(void) { return 1; }
 
 int LLVMFuzzerInitialize(int *argc, char ***argv) {
     PyConfig config;
-    PyConfig_InitIsolatedConfig(&config);
+    PyConfig_InitPythonConfig(&config);
     PyStatus status;
-    wchar_t* wide_program_name = Py_DecodeLocale(*argv[0], NULL);
-    status = PyConfig_SetString(&config, &config.program_name,
-                                wide_program_name);
+    status = PyConfig_SetBytesString(&config, &config.program_name, *argv[0]);
     if (PyStatus_Exception(status)) {
-        PyConfig_Clear(&config);
-        Py_ExitStatusException(status);
+        goto fail;
     }
 
+    status = Py_InitializeFromConfig(&config);
+    if (PyStatus_Exception(status)) {
+        goto fail;
+    }
+    PyConfig_Clear(&config);
     return 0;
+fail:
+    PyConfig_Clear(&config);
+    Py_ExitStatusException(status);
 }
 
 /* Fuzz test interface.
@@ -433,13 +438,6 @@ int LLVMFuzzerInitialize(int *argc, char ***argv) {
    (And we bitwise or when running multiple tests to verify that normally we
    only return 0.) */
 int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
-    if (!Py_IsInitialized()) {
-        /* LLVMFuzzerTestOneInput is called repeatedly from the same process,
-           with no separate initialization phase, sadly, so we need to
-           initialize CPython ourselves on the first run. */
-        Py_InitializeEx(0);
-    }
-
     int rv = 0;
 
 #if !defined(_Py_FUZZ_ONE) || defined(_Py_FUZZ_fuzz_builtin_float)