LineDissolver: Create geometries with dimensions matching input (#1373)

* LineDissolver: Create geometries with dimensions matching input

* LineDissolver: Create CoordinateSequence as shared_ptr

Author: dbaston

include/geos/dissolve/LineDissolver.h

@@ -83,6 +83,8 @@ class GEOS_DLL LineDissolver {
     std::vector<std::unique_ptr<LineString>> lines;
     std::stack<HalfEdge*> nodeEdgeStack;
     DissolveHalfEdge* ringStartEdge = nullptr;
+    bool constructZ = false;
+    bool constructM = false;
 
 
     void computeResult();
@@ -136,7 +138,7 @@ class GEOS_DLL LineDissolver {
 
     void buildRing(HalfEdge* eStartRing);
 
-    void addLine(std::unique_ptr<CoordinateSequence>& cs);
+    void addLine(const std::shared_ptr<CoordinateSequence>& cs);
 
 
 public:

src/dissolve/LineDissolver.cpp

@@ -88,6 +88,8 @@ void
 LineDissolver::add(const LineString* lineString)
 {
     const CoordinateSequence* seq = lineString->getCoordinatesRO();
+    constructZ |= seq->hasZ();
+    constructM |= seq->hasM();
 
     bool doneStart = false;
     for (std::size_t i = 1; i < seq->size(); i++) {
@@ -200,7 +202,7 @@ LineDissolver::updateRingStartEdge(DissolveHalfEdge* e)
 void
 LineDissolver::buildLine(HalfEdge* eStart)
 {
-    std::unique_ptr<CoordinateSequence> line(new CoordinateSequence(0, 4));
+    auto line = std::make_shared<CoordinateSequence>(0, constructZ, constructM);
     DissolveHalfEdge* e = static_cast<DissolveHalfEdge*>(eStart);
     ringStartEdge = nullptr;
 
@@ -238,7 +240,7 @@ LineDissolver::buildLine(HalfEdge* eStart)
 void
 LineDissolver::buildRing(HalfEdge* eStartRing)
 {
-    std::unique_ptr<CoordinateSequence> line(new CoordinateSequence(0, 4));
+    auto line = std::make_shared<CoordinateSequence>(0, constructZ, constructM);
     HalfEdge* e = eStartRing;
 
     // add first node
@@ -265,9 +267,9 @@ LineDissolver::buildRing(HalfEdge* eStartRing)
 
 /* private */
 void
-LineDissolver::addLine(std::unique_ptr<CoordinateSequence>& cs)
+LineDissolver::addLine(const std::shared_ptr<CoordinateSequence>& cs)
 {
-    auto ls = factory->createLineString(std::move(cs));
+    auto ls = factory->createLineString(cs);
     lines.emplace_back(ls.release());
 }
 

tests/unit/coverage/CoverageCleanerTest.cpp

@@ -77,6 +77,8 @@ struct test_coveragecleaner_data {
     {
         ensure_equals("checkEqual sizes", actual.size(), expected.size());
         for (std::size_t i = 0; i < actual.size(); i++) {
+            ensure_equals("hasZ does not match", actual[i]->hasZ(), expected[i]->hasZ());
+            ensure_equals("hasM does not match", actual[i]->hasM(), expected[i]->hasM());
             ensure_equals_geometry(actual[i], expected[i]);
         }
     }