[darcs-users] force commuting in practice

[Ben Franksen]

Am 14.06.19 um 23:52 schrieb Ganesh Sittampalam:
> The best way I know of doing it at the moment is this:
> 
> 1. Make a clone of the repository.
> 2. Use rebase to suspend B
> 3. Obliterate A
> 4. Unsuspend B
> 5. Resolve conflicts and amend B to make B'
> 6. Pull in A from the clone.
> 7. Resolve conflicts and amend A to make A'
> 
> The conflict resolution in step 7 is particularly annoying as it could
> be logically deduced from the resolution in step 5.
> 
> Does anyone have a better way?

I think the following /should/ work:

1. clone the repository
2. suspend A and B
3. pull A and B from the clone
4. again suspend A and B

We now have suspended: A;B;A;B

5. rebase obliterate the first A and the last B
6. rebase unsuspend the remaining B;A

However, this does not (currently) work for two reasons.

The first is that we cannot rebase obliterate the last B. I think this
is a bug in the patch selection for rebase obliterate. We can work
around this with

5'. rebase obliterate the first A
6'. rebase unsuspend B;A
7'. rebase obliterate the remaining suspended B

However, when I tried this, the resulting B' was missing some changes.
And on unsuspend of B;A it tells me there are conflicts but there are no
conflict markups. For the test if used

> darcs log -v
patch f41bf21d0d6027ff8f9de1dbb3b6b64b098c953c
Author: Ben Franksen <ben.franksen at online.de>
Date:   Sun Jun 16 14:15:25 CEST 2019
  * bar
    hunk ./f 1
    -foo
    +bar

patch 16f117520aac3b17e34dc6f204a25d08e807833f
Author: Ben Franksen <ben.franksen at online.de>
Date:   Sun Jun 16 14:15:05 CEST 2019
  * foo
    addfile ./f
    hunk ./f 1
    +foo

and what I got after my attempt at force-commute was

ben at juliana[1]:.../force-commute/T>darcs log -v
patch de6e6b1489f0c7f5a4eb763e84221df88b79db8c
Author: Ben Franksen <ben.franksen at online.de>
Date:   Sun Jun 16 14:15:05 CEST 2019
  * foo
    hunk ./f 1
    +foo

patch cc5c5ebff7c4b42719dadb8a7e918d3f0f111e45
Author: Ben Franksen <ben.franksen at online.de>
Date:   Sun Jun 16 14:15:25 CEST 2019
  * bar
    addfile ./f

Note the missing

    +bar

here.

Cheers
Ben