SF 1193128: Let str.translate(None) be an identity transformation
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 64be0de..63e1381 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -2344,10 +2344,10 @@
string_translate(PyStringObject *self, PyObject *args)
{
register char *input, *output;
- register const char *table;
+ const char *table;
register Py_ssize_t i, c, changed = 0;
PyObject *input_obj = (PyObject*)self;
- const char *table1, *output_start, *del_table=NULL;
+ const char *output_start, *del_table=NULL;
Py_ssize_t inlen, tablen, dellen = 0;
PyObject *result;
int trans_table[256];
@@ -2358,9 +2358,13 @@
return NULL;
if (PyString_Check(tableobj)) {
- table1 = PyString_AS_STRING(tableobj);
+ table = PyString_AS_STRING(tableobj);
tablen = PyString_GET_SIZE(tableobj);
}
+ else if (tableobj == Py_None) {
+ table = NULL;
+ tablen = 256;
+ }
#ifdef Py_USING_UNICODE
else if (PyUnicode_Check(tableobj)) {
/* Unicode .translate() does not support the deletechars
@@ -2374,7 +2378,7 @@
return PyUnicode_Translate((PyObject *)self, tableobj, NULL);
}
#endif
- else if (PyObject_AsCharBuffer(tableobj, &table1, &tablen))
+ else if (PyObject_AsCharBuffer(tableobj, &table, &tablen))
return NULL;
if (tablen != 256) {
@@ -2403,7 +2407,6 @@
dellen = 0;
}
- table = table1;
inlen = PyString_GET_SIZE(input_obj);
result = PyString_FromStringAndSize((char *)NULL, inlen);
if (result == NULL)
@@ -2411,7 +2414,7 @@
output_start = output = PyString_AsString(result);
input = PyString_AS_STRING(input_obj);
- if (dellen == 0) {
+ if (dellen == 0 && table != NULL) {
/* If no deletions are required, use faster code */
for (i = inlen; --i >= 0; ) {
c = Py_CHARMASK(*input++);
@@ -2425,8 +2428,13 @@
return input_obj;
}
- for (i = 0; i < 256; i++)
- trans_table[i] = Py_CHARMASK(table[i]);
+ if (table == NULL) {
+ for (i = 0; i < 256; i++)
+ trans_table[i] = Py_CHARMASK(i);
+ } else {
+ for (i = 0; i < 256; i++)
+ trans_table[i] = Py_CHARMASK(table[i]);
+ }
for (i = 0; i < dellen; i++)
trans_table[(int) Py_CHARMASK(del_table[i])] = -1;