Merge pull request #4911 from myk002/myk_pathable

[pathable] fix wagon pathability calculation for stairs and doors

docs/changelog.txt

@@ -68,6 +68,7 @@ Template for new versions:
 - `regrass`: no longer add all compatible grass types when using ``--force`` without ``--new``
 - `regrass`: ``--mud`` now converts muddy slade to grass, consistent with normal DF behavior
 - `gui/pathable`: fix hang when showing trade depot wagon access and a trade depot is submerged under water
+- `gui/pathable`: fix incorrect calculation of wagon paths over stairs and through doors
 
 ## Misc Improvements
 - `sort`: can now search for stockpiles on the Places>Stockpile tab by name, number, or enabled item categories

plugins/pathable.cpp

@@ -204,18 +204,22 @@ struct FloodCtx {
 
 static bool is_wagon_traversible(FloodCtx & ctx, const df::coord & pos, const df::coord & prev_pos) {
     if (auto bld = Buildings::findAtTile(pos)) {
-        if (bld->getType() == df::building_type::Trap)
+        auto btype = bld->getType();
+        if (btype == df::building_type::Trap || btype == df::building_type::Door)
             return false;
     }
 
-    if (ctx.wgroup == Maps::getWalkableGroup(pos))
-        return true;
-
     auto tt = Maps::getTileType(pos);
     if (!tt)
         return false;
 
     auto shape = tileShape(*tt);
+    if (shape == df::tiletype_shape::STAIR_UP || shape == df::tiletype_shape::STAIR_UPDOWN)
+        return false;
+
+    if (ctx.wgroup == Maps::getWalkableGroup(pos))
+        return true;
+
     if (shape == df::tiletype_shape::RAMP_TOP ) {
         df::coord pos_below = pos + df::coord(0, 0, -1);
         if (Maps::getWalkableGroup(pos_below)) {