Emily Shaffer <emilyshaffer@xxxxxxxxxx> writes: > Teach submodules a reference to their superproject's gitdir. This allows > us to A) know that we're running from a submodule, and B) have a > shortcut to the superproject's vitals, for example, configs. > > By using a relative path instead of an absolute path, we can move the > superproject directory around on the filesystem without breaking the > submodule's cache. > > Since this cached value is only introduced during new submodule creation > via `git submodule add`, though, there is more work to do to allow the > cache to be created at other times. > > Signed-off-by: Emily Shaffer <emilyshaffer@xxxxxxxxxx> > --- > Documentation/config/submodule.txt | 12 +++++++++ > builtin/submodule--helper.c | 4 +++ > t/t7400-submodule-basic.sh | 40 ++++++++++++++++-------------- > 3 files changed, 38 insertions(+), 18 deletions(-) > > diff --git a/Documentation/config/submodule.txt b/Documentation/config/submodule.txt > index d7a63c8c12..7c459cc19e 100644 > --- a/Documentation/config/submodule.txt > +++ b/Documentation/config/submodule.txt > @@ -90,3 +90,15 @@ submodule.alternateErrorStrategy:: > `ignore`, `info`, `die`. Default is `die`. Note that if set to `ignore` > or `info`, and if there is an error with the computed alternate, the > clone proceeds as if no alternate was specified. > + > +submodule.superprojectGitDir:: > + The relative path from the submodule's worktree to the superproject's > + gitdir. This config should only be present in projects which are > + submodules, but is not guaranteed to be present in every submodule. It > + is set automatically during submodule creation. > ++ > + In situations where more than one superproject references the same > + submodule worktree, the value of this config and the behavior of > + operations which use it are undefined. To reference a single project > + from multiple superprojects, it is better to create a worktree of the > + submodule for each superproject. You'd need to dedent the second paragraph that follows a lone '+' sign to typeset this correctly. The new paragraph suggests separate worktrees for the same submodule repository, but for that to work correctly, - "git clone [--recurse-submodules]" that clones the second superproject that shares the same submodule with a superproject that we already locally has to support a way for users to tell where to grab that existing submodule from and arrange a new worktree, instead of creating another instance of the submodule repository by cloning it afresh. - The "submodule.superprojectGitDir" needs to be set to per-worktree half of the repo-local configuration file. Because I usually do not pay much attention to the submodule part of the toolset, I may well be mistaken, but I suspect that the former does not exist yet. If I recall correctly, the latter was a NEEDSWORK item in the previous round of this patchset? As I said, I think it is OK for now to stop at declaring that you cannot simply do it without hinting something that may not fully work. Thanks.
