added binary stl file size check after ascii check

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

@@ -456,31 +456,61 @@ _STLReader_::
 check_stl_type(const std::string& _filename) const
 {
 
-  // open file
-  std::ifstream ifs (_filename.c_str(), std::ifstream::binary);
-  if(!ifs.good())
-  {
-    omerr() << "could not open file" << _filename << std::endl;
-    return NONE;
-  }
+   // open file
+   std::ifstream ifs (_filename.c_str(), std::ifstream::binary);
+   if(!ifs.good())
+   {
+     omerr() << "could not open file" << _filename << std::endl;
+     return NONE;
+   }
 
-  //find first non whitespace character
-  std::string line = "";
-  std::size_t firstChar;
-  while(line.empty() && ifs.good())
-  {
-    std::getline(ifs,line);
-    firstChar = line.find_first_not_of("\t ");
-  }
+   //find first non whitespace character
+   std::string line = "";
+   std::size_t firstChar;
+   while(line.empty() && ifs.good())
+   {
+     std::getline(ifs,line);
+     firstChar = line.find_first_not_of("\t ");
+   }
 
-  //check for ascii keyword solid
-  if(strnicmp("solid",&line[firstChar],5) == 0)
-  {
-    return STLA;
-  }
+   //check for ascii keyword solid
+   if(strnicmp("solid",&line[firstChar],5) == 0)
+   {
+     return STLA;
+   }
+   ifs.close();
 
-  //if the file does not start with solid it is STLB
-  return STLB;
+   //if the file does not start with solid it is probably STLB
+   //check the file size to verify it.
+
+   //open the file
+   FILE* in = fopen(_filename.c_str(), "rb");
+   if (!in) return NONE;
+
+   // determine endian mode
+   union { unsigned int i; unsigned char c[4]; } endian_test;
+   endian_test.i = 1;
+   bool swapFlag = (endian_test.c[3] == 1);
+
+
+   // read number of triangles
+   char dummy[100];
+   fread(dummy, 1, 80, in);
+   size_t nT = read_int(in, swapFlag);
+
+
+   // compute file size from nT
+   size_t binary_size = 84 + nT*50;
+
+   // get actual file size
+   size_t file_size(0);
+   rewind(in);
+   while (!feof(in))
+     file_size += fread(dummy, 1, 100, in);
+   fclose(in);
+
+   // if sizes match -> it's STLB
+      return (binary_size == file_size ? STLB : NONE);
 }