# incorporating the past 3 messages from 2007-04-09 to 2007-04-09. Participants: Thomas Hühn, Shawn O. Pearce, Junio C Hamano. Thread: https://gitlist.dev/t/7585 ## Thomas Hühn, 2007-04-09 18:14 Subject: incorporating the past Message-ID: <87d52d1kli.fsf@mid.thomas-huehn.de> URL: https://gitlist.dev/e/87d52d1kli.fsf%40mid.thomas-huehn.de ``` Hi I have looked through some git tutorials and the manual, and what is interesting me most right now is, how do I handle a situation like this with git? It's purely speculative, I don't have such a situation in reality, so my description might be a bit murky... I'll try to make an extremely simple example, just one file, no branching etc. I have a file under version control, that I got at the point of file version 1.0. I start committing changes: o--o--o--o--o--o--o ^ ^ git init, current, version 1.0 version 1.6 Then I get the history up to my version 1.0 from somewhere else (former maintainer, whatever). In the form of plain text files, one for each version; say, versions 0.1 thru 0.9. I want to incorporate this past into my tree. Can I just do another git init for 0.1, commit the changes up to 1.0 and merge those two histories? Don't I need a common ancestor for both or something like that? Or can I do the same, only up to 0.9 instead of 1.0, and then "sew together" those histories? Is there some kind of "add-past", where the changed contents in the working directory are prepended, not appended to the history? So that I could "prepend" 0.9, then 0.8 and so on until 0.1? I guess, I just don't have a clear grasp of what "history" and "branch" and so on mean. Thomas ``` ## Shawn O. Pearce, 2007-04-09 18:32 Subject: Re: incorporating the past Message-ID: <20070409183210.GX5436@spearce.org> URL: https://gitlist.dev/e/20070409183210.GX5436%40spearce.org In-Reply-To: <87d52d1kli.fsf@mid.thomas-huehn.de> ``` Thomas H??hn wrote: > I have a file under version control, that I got at the point of file > version 1.0. I start committing changes: > > o--o--o--o--o--o--o > ^ ^ > git init, current, > version 1.0 version 1.6 > > Then I get the history up to my version 1.0 from somewhere else (former > maintainer, whatever). In the form of plain text files, one for each > version; say, versions 0.1 thru 0.9. I want to incorporate this past > into my tree. > > Or can I do the same, only up to 0.9 instead of 1.0, and then "sew > together" those histories? Yes. Look at the `grafts' file. You can create a new repository of the 0.9..1.0 history, then graft that repository as a new parent of the 1.0 commit. This lets you join in the old history behind the existing history. The Linux kernel folks have done this for the kernel repository. -- Shawn. ``` ## Junio C Hamano, 2007-04-09 19:59 Subject: Re: incorporating the past Message-ID: <7vejmtz5dd.fsf@assigned-by-dhcp.cox.net> URL: https://gitlist.dev/e/7vejmtz5dd.fsf%40assigned-by-dhcp.cox.net In-Reply-To: <87d52d1kli.fsf@mid.thomas-huehn.de> ``` Thomas Hühn writes: > Can I just do another git init for 0.1, commit the changes up to 1.0 and > merge those two histories? Don't I need a common ancestor for both or > something like that? > > Or can I do the same, only up to 0.9 instead of 1.0, and then "sew > together" those histories? Yes. you can "graft" two distinct histories together. You already have v1.0..v1.6 history. You create v0.1..v0.9 history the same way, perhaps in a separate repository. Then, you tell git to pretend that the v1.0, which in reality does not have any parent (i.e. "git cat-file commit v1.0" does not have any "parent" line), has one parent that is v0.9, by creating a file .git/info/grafts. The file should list two commit object names (v1.0 first and then v0.9) separated with a single SP and then terminated with a single LF. Each line of this file says "this commit (the first one on the line) has the following parents (the rest)". ```