bug#31472: tsort reporting false loop in input. unix2dos fixes

[Ivan Ivanov]

> I've digged more into this, and I found that unix2dos doesn't fix
> the problem, but just masks the tsort behaviour.

> If you point the tsort result into a file, you will notice, that tsort
> breaks some of the newline chars. The input file seems to be ok. 

OK, I've worked on this. The input file is OK and the line breaks are
correct too. 

What I've have seen previously is, that tsort is adding LF in the
result file and is preserving the CRLF, so the file ends up with non
consistent line endings.

So we have two problems here:
1. tsort falsely reports loop 
2. When working on input with CRLF it creats a mess with the line
endings in the result file.

I am still curious why tsort doesn't report those loops when I change
the line endings to CRLF.

Hope this helps!

Ivan Ivanov