#417 STL importer does not correctly handle solids with no faces

[Bernhard Manfred Gruber]

Importing an STL file with a solid with no faces (e.g. via double-click in Windows Explorer) does not seem to be handled correctly. MeshLab shows a very large vertex count (looks like an uninitialized integer) and allocates loads of memory.

Example STL file:

solid anyname
endsolid anyname