- fix crash, if obj file contains degenerated faces

- added unittest for this case

closes #2382

git-svn-id: http://www.openmesh.org/svnrepo/OpenMesh/trunk@1236 fdac6126-5c0c-442c-9429-916003d36597

src/OpenMesh/Core/IO/reader/OBJReader.cc

@@ -64,6 +64,10 @@ using std::isspace;
 #include <string.h>
 #endif
 
+#include <set>
+#include <algorithm>
+#include <functional>
+
 //=== NAMESPACES ==============================================================
 
 
@@ -94,6 +98,28 @@ void trimString( std::string& _string) {
     _string = _string.substr( start, end-start+1 );
 }
 
+//-----------------------------------------------------------------------------
+template<typename Handle>
+class HasSeen : public std::unary_function <Handle, bool>
+{
+public:
+  HasSeen () : seen_ () { }
+
+  bool operator ()(const Handle& i) const
+  {
+    return (!seen_.insert(i.idx()).second);
+  }
+
+private:
+  mutable std::set<int> seen_;
+};
+
+// remove duplicated indices from one face
+void remove_duplicated_vertices(BaseImporter::VHandles& _indices)
+{
+  _indices.erase(std::remove_if(_indices.begin(),_indices.end(),HasSeen<BaseImporter::VHandles::value_type>()),_indices.end());
+}
+
 //-----------------------------------------------------------------------------
 
 _OBJReader_::
@@ -575,7 +601,11 @@ read(std::istream& _in, BaseImporter& _bi, Options& _opt)
       // note that add_face can possibly triangulate the faces, which is why we have to
       // store the current number of faces first
       size_t n_faces = _bi.n_faces();
-      fh = _bi.add_face(faceVertices);
+      remove_duplicated_vertices(faceVertices);
+
+      //A minimum of three vertices are required.
+      if (faceVertices.size() > 2)
+        fh = _bi.add_face(faceVertices);
 
       if (!vhandles.empty() && fh.is_valid() )
         _bi.add_face_texcoords(fh, vhandles[0], face_texcoords);

src/Unittests/TestFiles/cube-minimal-degenerated.obj

@@ -0,0 +1,29 @@
+g cube
+v  0.0  0.0  0.0
+v  0.0  0.0  1.0
+v  0.0  1.0  0.0
+v  0.0  1.0  1.0
+v  1.0  0.0  0.0
+v  1.0  0.0  1.0
+v  1.0  1.0  0.0
+v  1.0  1.0  1.0
+vn  0.0  0.0  1.0
+vn  0.0  0.0 -1.0
+vn  0.0  1.0  0.0
+vn  0.0 -1.0  0.0
+vn  1.0  0.0  0.0
+vn -1.0  0.0  0.0
+f  1//2  7//2  5//2
+f  1//2  3//2  7//2 
+f  1//6  4//6  3//6 
+f  1//6  2//6  4//6 
+f  3//3  8//3  7//3 
+f  3//3  4//3  8//3 
+f  5//5  7//5  8//5 
+f  5//5  8//5  6//5 
+f  1//4  5//4  6//4 
+f  1//4  6//4  2//4 
+f  2//1  6//1  8//1  8//1 2//1
+f  2//1  8//1  4//1 
+f  2//1  2//1  2//1 
+f  2//1  8//1  2//1 

src/Unittests/unittests_read_write_OBJ.cc

@@ -47,6 +47,22 @@ TEST_F(OpenMeshReadWriteOBJ, LoadSimpleOBJ) {
     EXPECT_EQ(12u , mesh_.n_faces()) << "The number of loaded faces is not correct!";
 }
 
+/*
+ * Just load a obj file of a cube with degenerated faces
+ */
+TEST_F(OpenMeshReadWriteOBJ, LoadDegeneratedOBJ) {
+
+    mesh_.clear();
+
+    bool ok = OpenMesh::IO::read_mesh(mesh_, "cube-minimal.obj");
+
+    EXPECT_TRUE(ok) << "Unable to load cube-minimal.obj";
+
+    EXPECT_EQ(8u  , mesh_.n_vertices()) << "The number of loaded vertices is not correct!";
+    EXPECT_EQ(18u , mesh_.n_edges()) << "The number of loaded edges is not correct!";
+    EXPECT_EQ(12u , mesh_.n_faces()) << "The number of loaded faces is not correct!";
+}
+
 /*
  * Just load a obj file of a cube and checks the halfedge and vertex normals
  */