diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c index af4ce6383c4..886d0249c7f 100644 --- a/Objects/unicodeobject.c +++ b/Objects/unicodeobject.c @@ -12253,9 +12253,9 @@ unicode_subscript(PyUnicodeObject* self, PyObject* item) return unicode_getitem((PyObject*)self, i); } else if (PySlice_Check(item)) { Py_ssize_t start, stop, step, slicelength, cur, i; - const Py_UNICODE* source_buf; - Py_UNICODE* result_buf; - PyObject* result; + PyObject *result; + void *src_data, *dest_data; + int kind; if (PySlice_GetIndicesEx(item, PyUnicode_GET_LENGTH(self), &start, &stop, &step, &slicelength) < 0) { @@ -12272,22 +12272,20 @@ unicode_subscript(PyUnicodeObject* self, PyObject* item) } else if (step == 1) { return PyUnicode_Substring((PyObject*)self, start, start + slicelength); - } else { - source_buf = PyUnicode_AS_UNICODE((PyObject*)self); - result_buf = (Py_UNICODE *)PyObject_MALLOC(slicelength* - sizeof(Py_UNICODE)); - - if (result_buf == NULL) - return PyErr_NoMemory(); - - for (cur = start, i = 0; i < slicelength; cur += step, i++) { - result_buf[i] = source_buf[cur]; - } - - result = PyUnicode_FromUnicode(result_buf, slicelength); - PyObject_FREE(result_buf); - return result; } + /* General (less optimized) case */ + result = PyUnicode_New(slicelength, PyUnicode_MAX_CHAR_VALUE(self)); + if (result == NULL) + return NULL; + kind = PyUnicode_KIND(self); + src_data = PyUnicode_DATA(self); + dest_data = PyUnicode_DATA(result); + + for (cur = start, i = 0; i < slicelength; cur += step, i++) { + Py_UCS4 ch = PyUnicode_READ(kind, src_data, cur); + PyUnicode_WRITE(kind, dest_data, i, ch); + } + return result; } else { PyErr_SetString(PyExc_TypeError, "string indices must be integers"); return NULL;