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Fix naïve heuristic in unicode slicing (followup to 1b4f886dc9e2)

This commit is contained in:
Antoine Pitrou 2011-10-04 20:00:49 +02:00
parent 2b72f83877
commit 875f29bb95
1 changed files with 15 additions and 7 deletions
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22
Objects/unicodeobject.c
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@ -12258,7 +12258,8 @@ unicode_subscript(PyUnicodeObject* self, PyObject* item)
Py_ssize_t start, stop, step, slicelength, cur, i;
PyObject *result;
void *src_data, *dest_data;
int kind;
int src_kind, dest_kind;
Py_UCS4 ch, max_char;
if (PySlice_GetIndicesEx(item, PyUnicode_GET_LENGTH(self),
&start, &stop, &step, &slicelength) < 0) {
@ -12276,17 +12277,24 @@ unicode_subscript(PyUnicodeObject* self, PyObject* item)
return PyUnicode_Substring((PyObject*)self,
start, start + slicelength);
}
/* General (less optimized) case */
result = PyUnicode_New(slicelength, PyUnicode_MAX_CHAR_VALUE(self));
/* General case */
max_char = 127;
src_kind = PyUnicode_KIND(self);
src_data = PyUnicode_DATA(self);
for (cur = start, i = 0; i < slicelength; cur += step, i++) {
ch = PyUnicode_READ(src_kind, src_data, cur);
if (ch > max_char)
max_char = ch;
}
result = PyUnicode_New(slicelength, max_char);
if (result == NULL)
return NULL;
kind = PyUnicode_KIND(self);
src_data = PyUnicode_DATA(self);
dest_kind = PyUnicode_KIND(result);
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);
Py_UCS4 ch = PyUnicode_READ(src_kind, src_data, cur);
PyUnicode_WRITE(dest_kind, dest_data, i, ch);
}
return result;
} else {