Can't open ico file without extension

[xxiieao]

Hi,

Not sure this is a bug. We received a MiniMagick::Invalid error, when trying to convert an ICO file to PNG. That ico file doesn't has extension name though. It looks like minimagick can't identify an ICO file, if no extension in filename.

Manage to fix it by adding the ext parameter.

MiniMagick::Image.open(path, ".ico")