[git] Submodules

WIP documenting steps to introduce submodules in wrye-bash.

That's an elaboration of Convert a git folder to a submodule retrospectively? stackoverflow answer.

1. Clone and prune all but dev

First of all - if we want to convert a subfolder to a submodule we have to clone the repo:

$ git --version
git version 2.6.1.windows.1
$ git clone /c/Dropbox/eclipse_workspaces/python/wrye-bash compiled
Cloning into 'compiled'...
done.
$ cd compiled
$ git remote -v
origin  C:/Dropbox/eclipse_workspaces/python/wrye-bash (fetch)
origin  C:/Dropbox/eclipse_workspaces/python/wrye-bash (push)
$ git remote rm origin

This deleted all my remote branches too and since when I cloned I had utumno-wip checked out that's the only one that was left. I recreated dev, checked it out, deleted utumno-wip and run git gc.

This increased the compiled/ folder from 380,332,943 to 517,447,494 bytes. Throwing in the --aggressive switch reduced that to 504,360,458 bytes (while making foobar2000 jump like crazy). Third's the charm:

git gc --prune=now

103,653,306 bytes - let me throw git reflog expire --expire=now --all (same answer) - no real diff. And let's delete all tags - I had to add aggressive again to see a reduction - 103,340,621 bytes, unimportant.

All this time I was giving the size of compiled/ - what we care about is compiled/.git 75,081,955 with only the dev reference at https://github.com/wrye-bash/wrye-bash/commit/df2fcc5f95bc7bc2613a14cb996671f3b82dd2db

2. filter-branch

MrD@MrsD MINGW64 /c/Dropbox/eclipse_workspaces/python/compiled (dev)
$ git filter-branch --subdirectory-filter 'Mopy/bash/compiled/' --prune-empty -- --all
Rewrite 9e78dad5d177370f947560a6df3fbacde348fec1 (52/52)
Ref 'refs/heads/dev' was rewritten

And now on to remove the filter branch backup - one way rm -r .git/refs/original, another way:

git for-each-ref --format="%(refname)" refs/original/ | xargs -n 1 git update-ref -d.

but from the same page the safest is to just reclone:

MrD@MrsD MINGW64 /c/Dropbox/eclipse_workspaces/python
$ git clone --no-hardlinks  /c/Dropbox/eclipse_workspaces/python/compiled comp
Cloning into 'comp'...
done.
$ cd comp
$ git reflog expire --expire=now --all                                          
$ git gc --prune=now --aggressive

The .git folder is at 24,485,155 bytes - so the 52 commits in this repo account for the 33% of the repo. Great.

Remove origin, renamed dev to master and:

git remote add origin git@github.com:wrye-bash/compiled.git
git push -u origin master

(Note: to undo a git filter branch

git fetch . +refs/original/*:*

)

3. Add the submodule

$ git rm -r Mopy/bash/compiled/
rm 'Mopy/bash/compiled/7z.dll'
rm 'Mopy/bash/compiled/7z.exe'
rm 'Mopy/bash/compiled/CBash.dll'
rm 'Mopy/bash/compiled/libbsa32.dll'
rm 'Mopy/bash/compiled/libbsa64.dll'
rm 'Mopy/bash/compiled/loot32.dll'
rm 'Mopy/bash/compiled/lzma.exe'
$ git submodule add git@github.com:wrye-bash/compiled.git Mopy/bash/compiled
Cloning into 'Mopy/bash/compiled'...
remote: Counting objects: 184, done.
remote: Total 184 (delta 0), reused 0 (delta 0), pack-reused 184
Receiving objects: 100% (184/184), 23.33 MiB | 353.00 KiB/s, done.
Resolving deltas: 100% (111/111), done.
Checking connectivity... done.
warning: LF will be replaced by CRLF in .gitmodules.
The file will have its original line endings in your working directory.

As you see there is a line endings warning. So before adding the submodule tack a

*.gitmodules text eol=lf

line in the .gitattributes file.

Unfortunately github will not include the submodule contents in the zip file - I sent them a support ticket let's see what they say.