Use stable sort, since it is possible to have multiple tiles on the same

logical layer.

Also fix missed change from previous commit.

lib/libcc2/GameLogic.cpp

@@ -371,9 +371,10 @@ cc2::MoveState cc2::CheckMove(const MapData& map, const Tile* tile, int x, int y
 
         const Tile* peekBase = &peek->bottom();
         if (peekBase->type() == Tile::SteelWall || peekBase->type() == Tile::StyledWall
-                || peekBase->type() >= Tile::NUM_TILE_TYPES || peek->blockLayer() != nullptr
+                || peekBase->type() >= Tile::NUM_TILE_TYPES
                 || peek->haveTile({Tile::MirrorPlayer, Tile::MirrorPlayer2, Tile::BlueTank,
-                                   Tile::YellowTank})) {
+                                   Tile::YellowTank, Tile::DirtBlock, Tile::IceBlock,
+                                   Tile::DirBlock})) {
             // These tiles block ALL mobs
             continue;
         }

lib/libcc2/Map.cpp

@@ -258,7 +258,7 @@ std::vector<const cc2::Tile*> cc2::Tile::sortedLayers() const
         sorted.push_back(tp);
         tp = tp->lower();
     }
-    std::sort(sorted.begin(), sorted.end(), [](const Tile* t1, const Tile* t2) {
+    std::stable_sort(sorted.begin(), sorted.end(), [](const Tile* t1, const Tile* t2) {
         return t1->layer() < t2->layer();
     });
     return sorted;

lib/libcc2/Tileset.cpp

@@ -96,9 +96,8 @@ void CC2ETileset::drawAt(QPainter& painter, int x, int y, const cc2::Tile* tile,
                          bool allLayers) const
 {
     if (allLayers) {
-        std::vector<const cc2::Tile*> layers = tile->sortedLayers();
         bool needXray = false;
-        for (const cc2::Tile* lt : layers) {
+        for (const cc2::Tile* lt : tile->sortedLayers()) {
             cc2::Tile::DrawLayer lay = lt->layer();
             if ((lay == cc2::Tile::BaseLayer && lt->needXray())
                     || (lay == cc2::Tile::ItemLayer || lay == cc2::Tile::MobLayer))