Handling upstream versioning scheme 2.40c >> 2.40b >> 2.40

[Andrius Merkys <merkys@debian.org>]

Dear Mentors,

I am maintaining package c2x, which has the following versioning scheme:

2.40c >> 2.40b >> 2.40

This is correct order as per 'dpkg --compare-versions'. However, if I
add '+ds' repack suffix (I need to), the order becomes reversed. Thus
'uscan' behaves as expected because it knows how to remove the '+ds'
suffix, but 'dpkg-genchanges' complains:

dpkg-genchanges: warning: the current version (2.40c+ds-1) is earlier
than the previous one (2.40+ds-1)

The naming scheme could be adjusted to add '.' before the letter in
version string (2.40c -> 2.40.c), but I cannot craft a watch file which
could perform this.

Any pointers are welcome.

Best,
Andrius