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py/map: Fix bugs with deletion of elements from OrderedDict. 

There were 2 bugs, now fixed by this patch:
- after deleting an element the len of the dict did not decrease by 1
- after deleting an element searching through the dict could lead to
  a seg fault due to there being an MP_OBJ_SENTINEL in the ordered array
This commit is contained in:
Damien George 2017-03-03 11:21:19 +11:00
parent 845a80a6c8
commit 9275c18270
1 changed files with 8 additions and 3 deletions
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11
py/map.c
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@ -178,8 +178,14 @@ mp_map_elem_t *mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t
for (mp_map_elem_t *elem = &map->table[0], *top = &map->table[map->used]; elem < top; elem++) {
if (elem->key == index || (!compare_only_ptrs && mp_obj_equal(elem->key, index))) {
if (MP_UNLIKELY(lookup_kind == MP_MAP_LOOKUP_REMOVE_IF_FOUND)) {
elem->key = MP_OBJ_SENTINEL;
// keep elem->value so that caller can access it if needed
// remove the found element by moving the rest of the array down
mp_obj_t value = elem->value;
--map->used;
memmove(elem, elem + 1, (top - elem - 1) * sizeof(*elem));
// put the found element after the end so the caller can access it if needed
elem = &map->table[map->used];
elem->key = MP_OBJ_NULL;
elem->value = value;
}
return elem;
}
@ -187,7 +193,6 @@ mp_map_elem_t *mp_map_lookup(mp_map_t *map, mp_obj_t index, mp_map_lookup_kind_t
if (MP_LIKELY(lookup_kind != MP_MAP_LOOKUP_ADD_IF_NOT_FOUND)) {
return NULL;
}
// TODO shrink array down over any previously-freed slots
if (map->used == map->alloc) {
// TODO: Alloc policy
map->alloc += 4;