Merge branch 'fix-deferred-delete' into 'master'

Fix deferred vertex deletion, add unit tests.

GeometryKernel::collect_garbage used to first perform the TopologyKernel
garbage collection, usually shrinking its vertex_deleted_ member, then
accessed it using is_deleted() with the old vertex indices.

This caused out-of-bounds memory access (made visible by
cmake -DSTL_VECTOR_CHECKS=ON) and non-fast deletion also resulted in wrong
results, the remaining vertices had wrong coordinates.

See merge request !4

src/OpenVolumeMesh/Core/GeometryKernel.hh

@@ -107,13 +107,17 @@ public:
 
     virtual void collect_garbage()
     {
-        TopologyKernelT::collect_garbage();
-
-        for (unsigned int i = vertices_.size(); i > 0; --i)
-            if (TopologyKernelT::is_deleted(VertexHandle(i-1)))
-            {
-                vertices_.erase(vertices_.begin() + (i-1));
-            }
+        if (TopologyKernel::fast_deletion_enabled()) {
+            TopologyKernelT::collect_garbage();
+            vertices_.resize(TopologyKernel::n_vertices());
+        } else {
+            for (unsigned int i = vertices_.size(); i > 0; --i)
+                if (TopologyKernelT::is_deleted(VertexHandle(i-1)))
+                {
+                    vertices_.erase(vertices_.begin() + (i-1));
+                }
+            TopologyKernelT::collect_garbage();
+        }
 
     }
 

src/Unittests/unittests_basics.cc

@@ -2002,3 +2002,22 @@ TEST_F(PolyhedralMeshBase, SwapVertices) {
 	EXPECT_EQ(12u, mesh_.n_vertices());
 }
 
+void testDeferredDelete(PolyhedralMesh &mesh) {
+	mesh.add_vertex(Vec3d(1,0,0));
+	mesh.add_vertex(Vec3d(0,1,0));
+	mesh.delete_vertex(VertexHandle(0));
+	mesh.collect_garbage();
+	EXPECT_DOUBLE_EQ(mesh.vertex(VertexHandle(0))[1], 1);
+}
+
+TEST_F(PolyhedralMeshBase, DeferredDelete) {
+	mesh_.enable_deferred_deletion(true);
+	mesh_.enable_fast_deletion(false);
+	testDeferredDelete(mesh_);
+}
+TEST_F(PolyhedralMeshBase, DeferredFastDelete) {
+	mesh_.enable_deferred_deletion(true);
+	mesh_.enable_fast_deletion(true);
+	testDeferredDelete(mesh_);
+}
+