Prevent endless loop in PLY reader when unknown property types are read.

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

@@ -1240,13 +1240,15 @@ bool _PLYReader_::can_u_read(std::istream& _is) const {
 
           if (listIndexType == "uint8") {
             indexType = ValueTypeUINT8;
+          } else if (listIndexType == "uint16") {
+            indexType = ValueTypeUINT16;
           } else if (listIndexType == "uchar") {
             indexType = ValueTypeUCHAR;
           } else if (listIndexType == "int") {
             indexType = ValueTypeINT;
           } else {
             omerr() << "Unsupported Index type for property list: " << listIndexType << std::endl;
-                continue;
+            return false;
           }
 
           entryType = get_property_type(listEntryType, listEntryType);

src/Unittests/unittests_read_write_PLY.cc

@@ -728,4 +728,58 @@ TEST_F(OpenMeshReadWritePLY, LoadSimpleBinaryPLYWithExtraElements) {
 	EXPECT_EQ(12u, mesh_.n_faces()) << "The number of loaded faces is not correct!";
 
 }
+
+/*
+* Ignore a file that does not contain vertices and faces
+*/
+TEST_F(OpenMeshReadWritePLY, IgnoreNonMeshPlyFile) {
+
+    mesh_.clear();
+
+    std::stringstream data;
+    data << "ply" << "\n";
+    data << "format binary_little_endian 1.0" << "\n";
+    data << "comment Image data" << "\n";
+    data << "element image 0" << "\n";
+    data << "property list uint16 uint16 row" << "\n";
+    data << "end_header" << "\n";
+
+    OpenMesh::IO::Options options = OpenMesh::IO::Options::Binary;
+
+    bool ok = OpenMesh::IO::read_mesh(mesh_, data, ".ply", options);
+
+    EXPECT_TRUE(ok) << "This empty file should be readable without an error!";
+
+    EXPECT_EQ(0u, mesh_.n_vertices()) << "The number of loaded vertices is not correct!";
+    EXPECT_EQ(0u, mesh_.n_edges()) << "The number of loaded edges is not correct!";
+    EXPECT_EQ(0u, mesh_.n_faces()) << "The number of loaded faces is not correct!";
+}
+
+
+/*
+* Ignore a file that does not contain vertices and faces
+*/
+TEST_F(OpenMeshReadWritePLY, FailOnUnknownPropertyTypeForLists) {
+
+    mesh_.clear();
+
+    std::stringstream data;
+    data << "ply" << "\n";
+    data << "format binary_little_endian 1.0" << "\n";
+    data << "comment Image data" << "\n";
+    data << "element image 0" << "\n";
+    data << "property list blibb blubb row" << "\n";
+    data << "end_header" << "\n";
+
+    OpenMesh::IO::Options options = OpenMesh::IO::Options::Binary;
+
+    bool ok = OpenMesh::IO::read_mesh(mesh_, data, ".ply", options);
+
+    EXPECT_FALSE(ok) << "This file should fail to read!";
+
+    EXPECT_EQ(0u, mesh_.n_vertices()) << "The number of loaded vertices is not correct!";
+    EXPECT_EQ(0u, mesh_.n_edges()) << "The number of loaded edges is not correct!";
+    EXPECT_EQ(0u, mesh_.n_faces()) << "The number of loaded faces is not correct!";
+}
+
 }