flatten-merge history

Hi,

suppose the following history

     P - - - Q - - - - - R       <-extern

A -- - B - - - C - D - - - E   <-master
          \           \
           M ...       \         <-b1
                        \
                         W ...   <-b2

Note that master and extern do not have a common parent. Both histories are 'distinct', they do not share common files, so there can't be any merge conflicts. What i want to achieve is this history:

     P - - - Q - - - - - R       <-extern

A -P'- B'- Q'- C'- D'- R'- E'  <-master
          \           \
           M'...       \         <-b1
                        \
                         W'...   <-b2

The two histories should be merged in chronological order. So while master reflects P-Q-R, b2 should only reflect P-Q and b1 should only reflect P.

All my current attempts (surgery with git replace or interactive rebase combined with merging) were not successfull.

Any ideas?

Best regards Henning

Hi,

On Sat, Oct 25, 2014 at 2:31 PM, Henning Moll <newsScott@gmx.de> wrote:

Could you tell us why interactive rebase did not work? If there can't be any merge conflict between both histories, it should have worked without asking you to resolve any conflict.

Best, Christian.

Am 26.10.2014 um 06:46 schrieb Christian Couder:

First of all i have to admit that i did not i-rebase-merge, but i-rebase-cherrypick. Now i tried it with i-rebase-merge and it didn't work either. Here's my workflow, which i repeated for all commits of 'extern' (in chronological order'). For simplicity let's assume that there is a parent commit for 'A'

1. For P, A is the nearest prior commit on 'master'
2. on master: git rebase -i A^
3. change A from pick to edit. save. quit
4. git merge P
5. git rebase --continue

 From the perspective of 'master' this worked. But as all of the commits 
have been rewritten, the branches b1 and b2 no longer refer to 'master'. 
Branch b2, for example, still branches off at B and not B'. So after 
this action, my history looks like this:

     P - - - Q - - - - - R       <-extern
       \
A'- m - B'- - - C'- D'- - - E'  <-master

A - - - B - - - C - D
          \           \
           M ...       \         <-b1
                        \
                         W ...   <-b2

A and A' are nearly the same: they only differ in the new GIT_COMITTER_DATE. Now this is what i try to get (after only applying P):

     P - - - Q - - - - - R       <-extern
     \
A'- m - B'- - - C'- D'- - - E'  <-master
          \           \
           M'...       \         <-b1
                        \
                         W'...   <-b2

Regards Henning

Henning Moll <newsScott@gmx.de> writes:

You only rebased master, so b1 and b2 were unchanged. If you want to change b1 and b2 you have to rebase them as well.

Andreas.

On Sun, Oct 26, 2014 at 4:19 PM, Andreas Schwab <schwab@linux-m68k.org> wrote:

Yeah. Henning, when interactively rebasing, in our editor, you should have something like:

pick A pick P pick B pick Q pick C pick D pick R pick E

which should work without any conflict. And then you can rebase the b1 and b2 branches on the resulting branch.

Best, Christian.

Am 26.10.2014 um 20:02 schrieb Christian Couder:

Thank you all very much. It worked!

I didn't know that i could also introduce new commits in the interactive rebase list. Just for the record, in case others need to do such a task:

intial situation:

     P - - - Q - - - - - R       <-extern

A - - - B - - - C - D - - - E   <-master
          \           \
           M ...       \         <-b1
                        \
                         W ...   <-b2

On master: $ git rebase -i --root

(editor opens showing

pick A pick B pick C pick D pick E

modify this to

pick A pick P pick B pick Q pick C pick D pick R pick E

save, quit. Now, master is already fixed. Now fix the branches:

$ git rebase --onto B' B b1 $ git rebase --onto D' D b2

Just a final question: Is it possible to keep the GIT_COMMITTER_DATE in all those rebases?

Thanks again Henning

Henning Moll <newsScott@gmx.de> writes:

If you want that you need to work with git filter-branch.

Andreas.