file type should be determined by MIME type, rather than by file extension

[bh9]

icp test test.txt produces test.txt identical to test, but because metalnx is interpreting the file extension, it deems these files different, test is application/octet-stream and test.txt is text/plain, this in turn means that test, a plaintext file, cannot be previewed but yet test.txt can

[mcv21]

[most UN*X platforms have the file utility, for example, which does this]