Why it is not allowed to undo or revert a file during merges?

[Anton 0]

Why it is allowed to introduce new changes while merging but it is not allowed to undo existing changes from the source branch? Isn't it a non sense?

I often want to revert some occasional changes while merging but I am lazy to switch branches for this.

[calbzam 94]

Hi,

In Plastic, the basic unit is the changeset (not the file).

When you are running a merge, you are merging the whole changeset (not a subset of individual files). That's why you can't avoid to merge a specific file change during a merge.

We do that to keep the merge tracking. 

Regards,

Carlos.

 

[Anton 0]

23 hours ago, calbzam said:

In Plastic, the basic unit is the changeset (not the file).

When you are running a merge, you are merging the whole changeset (not a subset of individual files). That's why you can't avoid to merge a specific file change during a merge.

We do that to keep the merge tracking.

Thank you Carlos!

But this is a matter of UX (behind the scenes you can do anything you have to to comply requirements of your server).

And it is still not clear why I can introduce new changes to the merge. I mean I can copy-paste old content of a file doing a manual revert, right? Why cannot you allow us to do the same thing in a straight forward way through undo?

[calbzam 94]

Hi,

This behavior is a core thing. In Plastic 3 (very old Plastic version) the merges were handled per file. It was a pain. In terms of performance and simplicity for the merge tracking the merges are currently handled per changeset (the changeset is the basic unit). 

I the following thread we also handled this topic:

 

Quote

Changesets are atomic, you can't cherry pick individual files from them, because then the merge tracking would fall apart.  We went from a non-atomic system (Clearcase) to Plastic and it took a while for people to grasp the concept. 

Regards,

Carlos.