Merged repo for protocol headers? Why are they split?

[Emil Velikov]

On 28 November 2017 at 12:38, Daniel Martin <consume.noise at gmail.com> wrote:
> On 27 November 2017 at 23:18, Peter Hutterer <peter.hutterer at who-t.net> wrote:
>> On Mon, Nov 27, 2017 at 09:07:12PM +0100, Daniel Martin wrote:
>>> On 22 November 2017 at 07:45, Adam Jackson <ajax at nwnk.net> wrote:
>>> > On Wed, 2017-11-22 at 10:25 +1000, Peter Hutterer wrote:
>>> >> On Tue, Nov 21, 2017 at 03:28:20PM -0800, Dylan Baker wrote:
>>> >> > Your script splits each proto into a subdirectory, does it really make sense to
>>> >> > do that, or should the final proto package have everything together in the root?
>>> >>
>>> >> please no! if you merge all repos the history will be messy. With subdirectories
>>> >> at least you get a nice git log for each individual repo if you specify the
>>> >> directory name.
>>> >
>>> > Agreed, that'd be a useful property to preserve given how random the
>>> > repo and file names are.
>>>
>>> Just started to test an idea today, to get an even better history. The
>>> idea is basically (omitting details):
>>> 1. format-patch each commit into a patch, the filename includes the
>>> commit time (UTC)
>>>    - patches of all repos become sorted and when applying them we get
>>> a nice history
>>> 2. hammer with sed on the patches
>>>    - add a proto prefix to the subject
>>>    - change initial position of files (i.e. move headers into
>>> include/X11/..., txts into doc/), no need to move files later
>>
>> if there are any commit messages that reference others ("Reverts commit
>> abcd123") you lose the reference because the sha is now different. so I'd
>> rather not do a re-commit of everything.
>>
>>> Surprisingly, this works pretty good for the first commits (reduced
>>> testing surface for the beginning). Last stop was at renames of files.
>>> But, I got another idea, which I can test tomorrow.
>>>
>>> The merge into subdirs looks straight forward and we can do that if I
>>> find a show-stopper. Deal?
>>
>> have you looked at subtree merges? Keeps the repo history for each merged
>> repository and the one from the top-level repository. And it forces you to
>> merge into a directory anyway, so that's a win right there.
>
> Oh? No, didn't knew that before. But, tested it:
> $ git remote add -f randrproto
> git://anongit.freedesktop.org/xorg/proto/randrproto
> $ git subtree add --prefix=randrproto/ randrproto master
>
> The history in the toplevel looks good. But, log -p shows the original
> paths in the commits. Okay, it doesn't rewrite history. I can deal
> with that.
> Though,
> $ git log (--graph) randrproto/randr.h
> just shows one commit from the subtree add.
>
One reasonably easy way to fold the repositories [while preserving all
the history] is via git filter-branch.
See xserver commit 35dc7c75150733dbcef8a18b6796f49a7c48ebee which
imports modesetting.

One could even script the process ;-)
Emil