Re: Question about merge & cherry pick

[Julien Maurel <julien@maurel.me>]

Ok, I didn't have this vision about how merge is apply, thanks.
There is no option to merge by considering each commit individually ?
Rebase do it but not applicable in my case :)
Thanks.

Le 07/11/2024 à 07:37, Johannes Sixt a écrit :
> Am 06.11.24 um 21:24 schrieb Julien Maurel:
>>  From my point of view, after these operations, content on branch master
>> and dev should be same with "zZz" on second line and "eDe" on last one.
>> But it's not the case on second line...
> The behavior that you observe is as intended and not a bug.
>
> You have this (consider each letter on its own line):
>
>            A Z Q E       initial commit
>           /       \
>       A Y Q E      |     dev: Z -> Y
>          |         |
>          |     A Y Q E   master: cherry-pick Z -> Y
>          |         |
>       A Z Q D      |     dev: revert Y -> Z and change E -> D
>           \        /
>            A Y Q D       merge
>
> Your expectation that the merge result is "A Z Q D" is wrong. Consider
> what happened on the dev branch (left) since the branches diverged:
> Since the change from Z to Y was reverted to Z, the only change that the
> dev side contributes to the merge is that of E to D. The master side, on
> the other hand, contributes the change of Z to Y. So the total of the
> merge must be Z to Y from the master side and E to D from the dev side,
> and that is what you get.
>
> A merge does not consider the individual changes on the branches, but
> only the differences since the merge base. For the merge operation, the
> change from Z to Y never happened on the dev side. The reversal of Y to
> Z is not visible for the merge and cannot contribute to the result.
>
> -- Hannes
>