Fix overlay heuristic for GeometryCollections with empty elements

include/geos/geom/HeuristicOverlay.h

@@ -46,11 +46,25 @@ class StructuredCollection {
 
 public:
 
+    static std::unique_ptr<Geometry> overlay(const Geometry* g0, const Geometry* g1, int opCode);
+
+private:
+
+    const GeometryFactory* factory;
+    std::vector<const Geometry*> pts;
+    std::vector<const Geometry*> lines;
+    std::vector<const Geometry*> polys;
+    std::unique_ptr<Geometry> pt_union;
+    std::unique_ptr<Geometry> line_union;
+    std::unique_ptr<Geometry> poly_union;
+    Dimension::DimensionType dimension;
+
     StructuredCollection(const Geometry* g)
         : factory(g->getFactory())
         , pt_union(nullptr)
         , line_union(nullptr)
         , poly_union(nullptr)
+        , dimension(Dimension::DONTCARE)
     {
         readCollection(g);
         unionByDimension();
@@ -61,8 +75,19 @@ class StructuredCollection {
         , pt_union(nullptr)
         , line_union(nullptr)
         , poly_union(nullptr)
+        , dimension(Dimension::DONTCARE)
     {};
 
+    Dimension::DimensionType getDimension() const
+    {
+        return dimension;
+    };
+
+    void addDimension(Dimension::DimensionType dim);
+    std::unique_ptr<Geometry> doUnaryUnion(int resultDim) const;
+    std::unique_ptr<Geometry> computeResult(StructuredCollection& coll, int opCode,
+                Dimension::DimensionType dimA, Dimension::DimensionType dimB) const;
+
     void readCollection(const Geometry* g);
     const Geometry* getPolyUnion()  const { return poly_union.get(); }
     const Geometry* getLineUnion()  const { return line_union.get(); }
@@ -72,22 +97,9 @@ class StructuredCollection {
     std::unique_ptr<Geometry> doIntersection(const StructuredCollection& a) const;
     std::unique_ptr<Geometry> doSymDifference(const StructuredCollection& a) const;
     std::unique_ptr<Geometry> doDifference(const StructuredCollection& a) const;
-    std::unique_ptr<Geometry> doUnaryUnion() const;
 
     static void toVector(const Geometry* g, std::vector<const Geometry*>& v);
     void unionByDimension(void);
-
-
-private:
-
-    const GeometryFactory* factory;
-    std::vector<const Geometry*> pts;
-    std::vector<const Geometry*> lines;
-    std::vector<const Geometry*> polys;
-    std::unique_ptr<Geometry> pt_union;
-    std::unique_ptr<Geometry> line_union;
-    std::unique_ptr<Geometry> poly_union;
-
 };
 
 

src/geom/Geometry.cpp

@@ -619,43 +619,6 @@ Geometry::intersection(const Geometry* other) const
 std::unique_ptr<Geometry>
 Geometry::Union(const Geometry* other) const
 {
-#ifdef SHORTCIRCUIT_PREDICATES
-    // if envelopes are disjoint return a MULTI geom or
-    // a geometrycollection
-    if(! getEnvelopeInternal()->intersects(other->getEnvelopeInternal())) {
-//cerr<<"SHORTCIRCUITED-UNION engaged"<<endl;
-        const GeometryCollection* coll;
-
-        std::size_t ngeomsThis = getNumGeometries();
-        std::size_t ngeomsOther = other->getNumGeometries();
-
-        // Allocated for ownership transfer
-        std::vector<std::unique_ptr<Geometry>> v;
-        v.reserve(ngeomsThis + ngeomsOther);
-
-
-        if(nullptr != (coll = dynamic_cast<const GeometryCollection*>(this))) {
-            for(std::size_t i = 0; i < ngeomsThis; ++i) {
-                v.push_back(coll->getGeometryN(i)->clone());
-            }
-        }
-        else {
-            v.push_back(this->clone());
-        }
-
-        if(nullptr != (coll = dynamic_cast<const GeometryCollection*>(other))) {
-            for(std::size_t i = 0; i < ngeomsOther; ++i) {
-                v.push_back(coll->getGeometryN(i)->clone());
-            }
-        }
-        else {
-            v.push_back(other->clone());
-        }
-
-        return _factory->buildGeometry(std::move(v));
-    }
-#endif
-
     return HeuristicOverlay(this, other, OverlayNG::UNION);
 }
 
@@ -676,40 +639,6 @@ Geometry::difference(const Geometry* other) const
 std::unique_ptr<Geometry>
 Geometry::symDifference(const Geometry* other) const
 {
-    // if envelopes are disjoint return a MULTI geom or
-    // a geometrycollection
-    if(! getEnvelopeInternal()->intersects(other->getEnvelopeInternal()) && !(isEmpty() && other->isEmpty())) {
-        const GeometryCollection* coll;
-
-        std::size_t ngeomsThis = getNumGeometries();
-        std::size_t ngeomsOther = other->getNumGeometries();
-
-        // Allocated for ownership transfer
-        std::vector<std::unique_ptr<Geometry>> v;
-        v.reserve(ngeomsThis + ngeomsOther);
-
-
-        if(nullptr != (coll = dynamic_cast<const GeometryCollection*>(this))) {
-            for(std::size_t i = 0; i < ngeomsThis; ++i) {
-                v.push_back(coll->getGeometryN(i)->clone());
-            }
-        }
-        else {
-            v.push_back(this->clone());
-        }
-
-        if(nullptr != (coll = dynamic_cast<const GeometryCollection*>(other))) {
-            for(std::size_t i = 0; i < ngeomsOther; ++i) {
-                v.push_back(coll->getGeometryN(i)->clone());
-            }
-        }
-        else {
-            v.push_back(other->clone());
-        }
-
-        return _factory->buildGeometry(std::move(v));
-    }
-
     return HeuristicOverlay(this, other, OverlayNG::SYMDIFFERENCE);
 }