merging / integrating a subrepo into its parent

[Matt Harbison]

On Thu, 05 Jul 2018 05:46:59 -0400, Benoit Fouletier <benblo at gmail.com>  
wrote:

> I have the following structure:
> * main
>   * sub
>
> sub is currently stored in a subrepo: now I would like to have it as a
> regular subfolder of main, with its history stored in main.
>
> I know I could use hg pull --force to add it as a parallel branch, then
> merge the heads, and the end result would look like this:
>     o-main1-main2-main2------------------o
>                                         /
>                         o-sub1-sub2-sub3

That's not quite the same either, because the 'sub' part of the path isn't  
actually stored in the subrepo, so you'd lose it on pull.  If you then try  
to rename those files to add 'sub' back in, you will run into problems  
when you update between a revision with a subrepo and a revision without  
the subrepo.

> ... but it feels like a shame to lose the main <-> sub relationship  
> tracked
> by .hgsubstate, so basically I would like to rewrite it to:
>     o-main1-sub1-main2-sub2-main2-sub3-o
> --> is there a way to achieve that? perhaps using hg convert?

Convert will work, but not out of the box.  If your subrepo is 1:1 with  
the parent (i.e. you used commit -S), then it should be relatively trivial  
to hack up the mercurial_source class to return all of the files,  
including from the subrepo.  I had a repo/subrepo pair that was pretty  
close to that, but there were a handful of subrepo commits that I piled up  
and then committed to the parent as a group.  I hacked the convert code to  
notice that a parent commit jumped more than one subrepo revision, and had  
the source class (and the main convert code) crawl the subrepo and create  
an equivalent commit so I didn't lose any commit messages.  But it was too  
tied to the repo I was converting to submit upstream.

> I am fine with rewriting history, changing hashes and recloning  
> everything.