py: Handle case of slice start > stop in common sequence function.

This commit is contained in:
Paul Sokolovsky 2014-05-25 02:29:40 +03:00
parent afaaf535e6
commit 69d081a7cf
2 changed files with 6 additions and 3 deletions

View File

@ -355,9 +355,6 @@ STATIC mp_obj_t str_subscr(mp_obj_t self_in, mp_obj_t index, mp_obj_t value) {
if (!mp_seq_get_fast_slice_indexes(self_len, index, &start, &stop)) {
assert(0);
}
if (start >= stop) {
return MP_OBJ_NEW_QSTR(MP_QSTR_);
}
return str_new(type, self_data + start, stop - start);
}
#endif

View File

@ -88,6 +88,12 @@ bool mp_seq_get_fast_slice_indexes(machine_uint_t len, mp_obj_t slice, machine_u
} else if (stop > len) {
stop = len;
}
// CPython returns empty sequence in such case, or point for assignment is at start
if (start > stop) {
stop = start;
}
*begin = start;
*end = stop;
return true;