Explicit revision numbers

[Holger]

Hi

As stated in an earlier topic on this list "How do I diff from 'add' to
rev 1.1?" ...
I've created a little python script to produce patches from log
messages - i.e.:
patchmaker "Bug 123"

In this script I parse the logs and I need to find out what previous
rev each new rev is based on. I do that like this:
    def calcPrevRev(self):
        # todo: get this from CVS instead of guessing
        self.prevrev = "0"
        ver = self.rev.split(".")
        n = int(ver.pop()) - 1
        while len(ver) >= 1:
            if n >= 1:
                ver.append(str(n))
                self.prevrev = ".".join(ver)
                break
            else:
                if len(ver) <= 1: # prevrev is null
                    break
                ver.pop() # throw this away
                n = int(ver.pop())

My question:
IRC I've read somewhere that you are able to explicitely specify new
revision number - e.g bump the major number - when checking in. Is this
still true?

Is there a better way than the above to figure prevrev out?

Help appreciated.

/Holger