Fix #12685: nullptr dereference when checking for equal loaded/loading groups. (#12686)

Always treat empty groups as non-equal. Given that the case of both being empty is handled earlier, they cannot both be equal and empty.

Additionally if a loaded or loading set are all the same, only add one reference.

(cherry picked from commit 856ec901ca9523812b16e367b49d2baf4a28d26b)
This commit is contained in:
Peter Nelson
2024-05-18 09:17:06 +01:00
committed by Jonathan G Rennison
parent 3df3ed6690
commit f62eb72fcb

View File

@@ -6204,10 +6204,9 @@ static void NewSpriteGroup(ByteReader *buf)
grfmsg(8, "NewSpriteGroup: + rg->loading[%i] = subset %u", i, loading[i]);
}
if (std::adjacent_find(loaded.begin(), loaded.end(), std::not_equal_to<>()) == loaded.end() &&
std::adjacent_find(loading.begin(), loading.end(), std::not_equal_to<>()) == loading.end() &&
loaded[0] == loading[0])
{
bool loaded_same = !loaded.empty() && std::adjacent_find(loaded.begin(), loaded.end(), std::not_equal_to<>()) == loaded.end();
bool loading_same = !loading.empty() && std::adjacent_find(loading.begin(), loading.end(), std::not_equal_to<>()) == loading.end();
if (loaded_same && loading_same && loaded[0] == loading[0]) {
/* Both lists only contain the same value, so don't create 'Real' sprite group */
act_group = CreateGroupFromGroupID(feature, setid, type, loaded[0]);
grfmsg(8, "NewSpriteGroup: same result, skipping RealSpriteGroup = subset %u", loaded[0]);
@@ -6220,11 +6219,13 @@ static void NewSpriteGroup(ByteReader *buf)
if (_action6_override_active) group->sg_flags |= SGF_ACTION6;
act_group = group;
if (loaded_same && loaded.size() > 1) loaded.resize(1);
for (uint16_t spriteid : loaded) {
const SpriteGroup *t = CreateGroupFromGroupID(feature, setid, type, spriteid);
group->loaded.push_back(t);
}
if (loading_same && loading.size() > 1) loading.resize(1);
for (uint16_t spriteid : loading) {
const SpriteGroup *t = CreateGroupFromGroupID(feature, setid, type, spriteid);
group->loading.push_back(t);