how do I commit somewhere other than onto a tip?

[Vincent Ladeuil]

>>>>> "Vincent" == Vincent Broman <broman at spawar.navy.mil> writes:

Hi Vincent,

    Vincent> I think I need the capability to commit versions
    Vincent> that are not successors of a tip revision, 

Basically you can't.

    Vincent> e.g. I want to commit a new version which should be
    Vincent> placed in between two successive versions already
    Vincent> committed, or else to place it ahead of all the
    Vincent> other versions, as a new version 1.  It might even
    Vincent> be a new branch off some parent version in the past.

Then create a new branch starting at the tip you're interested
in, commit there, and... either merge into your work-in-progress
trunk or merge in this new branch and makes it your new
work-in-progress trunk.

    Vincent> Why? I have inherited a piece of software to
    Vincent> maintain for which I have found many tens of copies
    Vincent> of the source in various stages of development,
    Vincent> stored in separate directory trees on various
    Vincent> machines or backups.

Been there, done that, you're in for quite a journey, good luck,
it's a tough job, but the reward is high.

    Vincent> From file modtimes and from looking at diffs, I have
    Vincent> an approximate idea of the order they should appear
    Vincent> in history.  I would like to get everything into a
    Vincent> version control system, to document it, but I cannot
    Vincent> just start with the earliest and try to retrace
    Vincent> everything from the big bang to the present in
    Vincent> order.

That's the root of your problem, you don't know what the real
history is/was. My advice would be: try and refine.

So you may want to keep track of two histories:

- the project history as you can reconstruct it, subject to
  changes as you get a better understanding,

- the history of your attempts to get there.

Give a try to bzr viz (available via the bzr-gtk plugin) and/or
bzr qlog (available via the qbzr plugin), it will show you the
history of a branch in a graphical way.

    Vincent> As I go through I may change my mind as to the
    Vincent> dependencies/order.

You may find the following interesting:

http://www.venge.net/mtn-wiki/DaggyFixes

It's related to you needs in that they explain how to apply bug
fixes at the Right Place (for various definitions of right :).

    Vincent> I may find an additional version on a dusty backup
    Vincent> after I have started.  I may only have time to
    Vincent> process the last 10-15 versions right now, then add
    Vincent> in the other older versions as I have time to
    Vincent> analyze them later.

Hence my proposal to handle two histories.

    Vincent> My basic problem is recording history
    Vincent> retrospectively, instead of as it happens.

Then build it as you think it happened and if you change your
mind, build it again.

    Vincent> Is this possible in Bazaar?

May be not as easily as you want, but yes, it's doable.

    Vincent> I do not like the idea of writing code to do surgery
    Vincent> on archives in ways they were not designed to allow,
    Vincent> but concatenating dump files is something subversion
    Vincent> sort-of allows.

John Arbash Meinel proposed a simpler approach using bzr-rebase
in another mail that you may prefer.

Both approaches have pro and cons, but trying both should help
you find the right balance.

Hope that helps,

     Vincent (vila)