python · methane · Jul 5, 2019 · Jul 5, 2019
diff --git a/Python/codecs.c b/Python/codecs.c
@@ -99,40 +99,38 @@ PyObject *normalizestring(const char *string)

 PyObject *_PyCodec_Lookup(const char *encoding)
 {
-    PyObject *result, *v;
-    Py_ssize_t i, len;
-
    if (encoding == NULL) {
        PyErr_BadArgument();
-        goto onError;
+        return NULL;
    }

    PyInterpreterState *interp = _PyInterpreterState_GET_UNSAFE();
-    if (interp->codec_search_path == NULL && _PyCodecRegistry_Init())
-        goto onError;
+    if (interp->codec_search_path == NULL && _PyCodecRegistry_Init()) {
+        return NULL;
+    }

    /* Convert the encoding to a normalized Python string: all
       characters are converted to lower case, spaces and hyphens are
       replaced with underscores. */
-    v = normalizestring(encoding);
-    if (v == NULL)
-        goto onError;
+    PyObject *v = normalizestring(encoding);
+    if (v == NULL) {
+        return NULL;
+    }
    PyUnicode_InternInPlace(&v);

    /* First, try to lookup the name in the registry dictionary */
-    result = PyDict_GetItemWithError(interp->codec_search_cache, v);
+    PyObject *result = PyDict_GetItemWithError(interp->codec_search_cache, v);
    if (result != NULL) {
        Py_INCREF(result);
        Py_DECREF(v);
        return result;
    }
    else if (PyErr_Occurred()) {
-        Py_DECREF(v);
-        return NULL;
+        goto onError;
    }

    /* Next, scan the search functions in order of registration */
-    len = PyList_Size(interp->codec_search_path);
+    const Py_ssize_t len = PyList_Size(interp->codec_search_path);
    if (len < 0)
        goto onError;
    if (len == 0) {
@@ -142,6 +140,7 @@ PyObject *_PyCodec_Lookup(const char *encoding)
        goto onError;
    }

+    Py_ssize_t i;
    for (i = 0; i < len; i++) {
        PyObject *func;

@@ -175,9 +174,11 @@ PyObject *_PyCodec_Lookup(const char *encoding)
        Py_DECREF(result);
        goto onError;
    }
+    Py_DECREF(v);
    return result;

 onError:
+    Py_DECREF(v);
    return NULL;
 }