Maintaining multi-layered, interdependent branches

[Ben Finney]

Ben Finney <bignose+hates-spam at benfinney.id.au> writes:

> Robert Collins <robertc at robertcollins.net> writes:
> 
> > switch upstream-checkout, bzr pull, bzr up-thread --auto top:
> 
> Why are those options needed for that ‘up-thread’ command?

I don't have such an option ‘--auto’ on my ‘up-thread’ command:

$ bzr version
Bazaar (bzr) 1.5

$ aptitude show bzr-loom | grep '^Version:'
Version: 1.4.0~bzr84-1

$ bzr help loom | grep -- '--auto' | wc -l
0

So, that tells me at least that there is something about the
‘up-thread’ command that needs to be done manually afterward, and that
some later version has an ‘--auto’ option to cover?

> If this is the general case, why does the command not do this in the
> absence of any options?

This question becomes more puzzling.

> > Arthur should 'bzr record' his loom before pushing it.
> 
> Are there irrevocable changes made by doing ‘record’? Or is it
> something that can safely be done at any time without changing the
> loom structure?
> 
> Does it make a difference which thread is current when Arthur issues
> the ‘record’ command?

I don't understand what ‘record’ does that isn't already covered by
‘commit’. The ‘README’ says:

    * record: similar to a standard bzr commit, this records the
      current stack of patches into the loom's version history,
      allowing it to be pushed, pulled and merged.

But isn't every change already recorded in version history by
‘commit’?

Or is there something different about “the loom's version history”
as distinct from “the branch's version history”? Perhaps I've failed
to read properly, but my reading of the documentation doesn't tell me
how a loom has some separate version history.

This is compounded by the fact that only *some* changes seem to need
altering anything but the branch version history:

> > 'bzr switch thread-to-send; bzr send -r thread:..-1'
> 
> Okay, so this *doesn't* include a ‘record’ step. Is that not
> necessary to send a patch bundle to Bernard? Remember that Bernard
> doesn't have looms.

Perhaps what is lacking is a clear deliniation of what about the
user's mental model needs to be changed when going from a non-loom
branch to a loom.

-- 
 \         “I went to the museum where they had all the heads and arms |
  `\      from the statues that are in all the other museums.” —Steven |
_o__)                                                           Wright |
Ben Finney