TKLBAM DirIndex incorrectly handles mtime

[OnGle]

It's not clear (to me) when this bug was introduced, it is possible that it's existed for the entire lifetime of tklbam.

The stat structure's mtime value is now almost always a float. Pre python 2.5 it was an int by default, 2.5 and after it is a float for all systems that support sub-second mtime values. Nowadays, most systems support sub-second mtime values afaik.

The mtime value is handled incorrectly in 2 places:
https://github.com/turnkeylinux/tklbam/blob/ec65887692fe336f121d95fdeb97c8dd31bd01e7/dirindex.py#L71
and
https://github.com/turnkeylinux/tklbam/blob/ec65887692fe336f121d95fdeb97c8dd31bd01e7/dirindex.py#L63

The latter is the real issue, this is the value that will be written to a file by dirindex. In python2, the %x format specifier will accept a float and silently truncate it, then format it as an integer in hex.

Because of this changes.whatschanged will report files as being different, even between a dirindex, and the same dirindex that has been saved to file.

[JedMeister]

Good find! As discussed offline, initially we'll convert tklbam to modern python - including any existing bugs such as this one. Then we can look at resolving them.